text:
Talk:Circuit Theory/Sinusoidal Sources

there are serious errors in there. Voltage is not the derivative of current, this is only true for specific components! V = L di/dt for inductors. I = C dv/dt for capacitors, V = IR for resistors.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:Circuit Theory/Sinusoidal Sources


text: Template:Goodbook/This Quantum World

title: Template:Goodbook/This Quantum World


text: Template:Goodbook/Stuttering

title: Template:Goodbook/Stuttering


text:
Talk:TI-Basic Z80 Programming/Archive

Combining Wikis
A while ago I started a TI-Basic wiki aptly named TI-Basic Developer because I didn't think there was a TI-Basic wiki on the Internet, but now that I know this wiki exists, I think it would be good to combine wikis. It seems rather pointless to have both wikis separately working towards the same goal, when we could just consolidate our efforts and create one single high-quality wiki.

While this TI-Basic wiki has some quality content, TI-Basic Developer actually has considerably more content and is further along in its development (please check it out and see for yourself), so I think it should be the wiki that is used. Every user here would be eligible to become a member, and the admins could keep their admin positions. I don't know who the admins are for this wiki, but could they please consider this offer and write a response back. You can also contact me by email at tibasicdev @ gmail. com (remove spaces). Thanks --Burr 13:03, 31 March 2007 (UTC)

TI-Basic vs traditional
You should definitely mention ticalc.org as it's resources are vast. Also, I think this would be helpful. Virtual TI. Is TI-Basic the same as Basic? Just wondering. --Gflores 01:49, 15 November 2005 (UTC)

 * TI-Basic is a version of BASIC... It works much the same way but some commands are changed, added or removed. Nilsmo 19:22, 19 November 2005 (UTC)

 * The basic used on the calculators is different from the more traditional basic. It has while loops and other features that I can't remember right now that traditional basic doesn't have. --Peterw 23:17, 22 November 2005 (UTC)

TI83/84 vs TI86 vs TI89
There are different versions of TI-BASIC depending on calculators. How should this be handled? (For example, GetKey codes are different in different graphing calculators.) Nilsmo 19:22, 19 November 2005 (UTC)

 * And by the way, seeing how the only true difference in programming on TI-83 compared to the TI-83 plus is that you can't use lower case and some catalogue features, I think we shouldn't limit the guide to just the plus, we can just mention the limitations and correctly label in the catalogue list (upcoming). Gtabmx 22:24, 20 November 2005 (UTC)

 * I think we could start each section with the general stuff and add subsections detailing the differences. Just an idea. I haven't programmed outside of the 83/84/+ line so I don't know how different it can get. Gdd 02:29, 22 November 2005 (UTC)

 * True, 83+ BASIC isn't much different from 83 BASIC, but the BASIC used on TI-89 calculators is very different from the code used on TI-83s. The command for clearing the screen is even different on the 89 and it will be quite hard to explain the major differences in, for example, menus and pixels for the two calculators. Since most of us, including myself, seem to be programming singularly for the 83+ line, I suggest this wikibook at least tell the reader that this tutorial is only designed for 83, 83+, 83+ Silver Edition, 84+ and 84+ Silver Edition calculators. Nilsmo 13:30, 27 November 2005 (UTC)

 * So... is this module focusing on the 83 Plus (and subsequently the regualr 83) or is it going to encompas as many calculators as possible? Or just 83/84 family? --Gtabmx 22:54, 1 December 2005 (UTC)

 * Yes. (I think) Nobody here owns an 89 so it would be impossible to teach that... 69.251.238.76 17:04, 3 December 2005 (UTC)

A volunteer
Hey, I have been programming in TI-BASIC for a long time and I will gladly conrtibute as much of my free time to building this Book up; however, some reorganizing must be done to make s easier to learn the commands as they are need in programming rather than as they appear in the lists (If should be followed with End along with Then and Else, and should be all on one page). Also, I think this is a great opportnity to create a Tricks/Tips page with a vast library of byte-saving shortcuts and efficiencies. Also, this is my first time making major updates to a Wiki document, so any info/help is appreciated, but since I learned all my TI-BASIC trhough trial and error and experimenting, I should be able to study other documents/additions and copy the way it is written. Gtabmx 00:39, 20 November 2005 (UTC)

Tricks
The tricks section is a good idea. Tricks that can be done using TI-BASIC are quite valuable, and, in some cases, necessary for a useful program. I know many of these so maybe I'll start a new section on them. Nilsmo 13:30, 27 November 2005 (UTC)

 * Just ballpark it, how many different Getkey possibilities do you think there are? I know of 4 or 5, but I've heard others talk about faster ways.  Do you know? (Gtabmx 16:25, 8 December 2005 (UTC))

Fix up Necessary Items
The Necessary Items page is now updated to include other computer software and ticalc.org but I wasn't logged in when I updated it so, yeah. Gtabmx 14:24, 21 November 2005 (UTC)

Overall plan and Layout
Are you sure this is the best layout. Could someone give an abstract of what each section is about? Which section will link ports be placed in? Gdd 02:29, 22 November 2005 (UTC)

 * Yeah, it is best to learn the language in the order from simple to more complex, of course, learning commands of the same category or that are used together (ie. If/Then/Else/End) at the same time or following each other. But what I don't understand is this, are we writing a book for programming in all TI-BASIC forms for all supporting calculators, or just for the 83/83Plus?  Also, I think that for those who want to learn from scratch can read from beginning to end, while those who need to learn only certain aspects can do so by using links.  Therefore, the layout must be in order, but must allow easy acess to all the disussed topics.  And by the way, I made a mistake in the IF section becuase it was late at nigth and I forgot to mention that when using End to close off If regulated instructions, there must be a Then after IF.  Anyway, I'll get around to adding and fixing soon, but the last two weeks of college are nuts.  Gtabmx 11:51, 29 November 2005 (UTC)

 * Great job to whomever added the links at the bottom of each page. Very useful.  So right now we should make a plan to organize both the pages and the TOC.  Also, is there another way to make boxes that look different from the pre /pre ones?  Gtabmx 11:00, 30 November 2005 (UTC)

 * I feel that Output should come before Input. And somewhere early we need the assignment operator (STO) --MathMan64 05:34, 1 December 2005 (UTC)

Alright, I've been thinking and taking others's suggestions so far into consideration and the current plan should be as follows: - Abstract - Introduction (including about TI-Basic, programming,      differences in versions, conventions used in module,       TI-Basic and overall computer lingo, ...) - Necessary Items - Variables (letters, strings, matrices, functions, ...      although we shouldn't force learning matrices on newcomers       since for most simple starting stuff, you may never use them.     - Output     - Input     - Criteria based instructions (starting with If/Then/Else/End, then While, then Repeat, then For(, and then IS>( and DS<(      optionnaly (I have personnaly never used them, but would like to).    - Other CTL commands (like Lbl/Goto, Pause, Stop, ... baisically the rest)    - The rest of the I/O commands in order of how easy they are to       understand/implement     - Then get into more advaned programming     - Trick, Tips, and Optimizations     - Conclusion Of course, people will surely find more to add, but I have class now...  (Gtabmx 13:27, 1 December 2005 (UTC))

 * IS>( and DS<( are mainly left over for compatibility with the original TI-81 which had very little decision and looping capability.--MathMan64 01:31, 8 December 2005 (UTC)

 * Right, so as a sole TI-83 Plus Basic programmer, I don't really "need" IS>( and DS<( ? Ok, makes no difference, I never understood the explanaitions on how to use them and frankly never felt the need to use them. (Gtabmx 13:14, 8 December 2005 (UTC))

Instructions sub-module size
I must suggest a change in the plan for the list of instructions. Having a whole module for each one does not seem appropriate to me. I like the content so far, and there is some more detail and an example or two that could be added. But even with that, a lot of them would consist only of two or three paragraphs - - a little small for a module.

Having a module for the CTL instructions and having the link to IF be TI-Basic:Instructions:CTL makes more sense (especially for those that are really small like Stop.) --MathMan64 05:28, 8 December 2005 (UTC)

 * You see, I wanted to do exactly that: have one CTL page and one I/O page so that not only would all the instructions be in one placed, but anything can be linked with the #IF an so on; however, this is the first time I write for Wiki and in a previous edit I tried to use the # somewhere in a link but I don't know how to use it properly. Can anyone explain how to link to sections within a wiki page?  I've checked the Wiki help section and they give no such information.  I agree this way of organizing the guide in much more efficient.  (Gtabmx 13:18, 8 December 2005 (UTC))

Input and GetKey
I agree with the present Table of Contents that GetKey should be a separate module. If so, we should move It's coverage from Input. --MathMan64 05:44, 8 December 2005 (UTC)

 * Yup, once we get a seperate CTL module and a seperate I/O module (then hopfully a Draw module and Vars module and so on) then we can have a line in it uder the Getkey section with a brief description of what the Getkey command does and link to the real Getkey module and link to the Tips, Tricks, and Optimizations module, where I can ganarntee will have many Getkey techniques. (Gtabmx 13:23, 8 December 2005 (UTC))

TI-Basic Wikibook conventions
I figure the modules and expalnations for each instrcution, as well as the overall presentation, should be written and displayed the same way no matter the topic or the writter, so we will need an agreed upon convention for writting the modules.

My suggestion is: -introduce the instruction (what it does an where to find it) -give its general form or forms (for example: line([initial x],[initial y],[final x],[final y]) and line([initial x],[initial y],[final x],[final y],0) for the line( instruction ) -explain how the calculator handles it -give explanations and examples of its uses (basic in the basic section and more advanced uses in the advanced section) and use the preview boxes -explain/demonstrate exceptions or irregularities (if applicapble) -link to other modules or sections in this Wikibook with relevant information to the instruction/information discussed -include the Previous and Next links along with the main page link to the table of contents.

I'll try to make the IF page I wrote look like this and who ever wants to make suggestion can, then we can begin writing them all (just can't believe how long it will take to complete the Catalogue page!!) Gtabmx 16:21, 8 December 2005 (UTC)

TI BASIC Advanced?
What about those of us who are really advanced? I'll write an advanced tutorial if you want me too--you can put it in wherever. If you don't think I'm advanced enough, e-mail me and I'll tell you about some games I made--maybe send you the coding if I have time. Look... ---A Cave game(not side scrolling, but hey, whatever) ---A 5-7 frames per second side-scroller (an Optimized SiCoDe WAR) ---A Nibbles game (I can make the snake take a dump with lethal crap) ---A puzzle game where you get from 1 pt to another avoiding spikes, and all you have is an anit-gravity suit And so on.... But don't mind me--I'm ranting, but I WILL write an advanced tutorial for this book. I've seen other advanced tutorials and stuff from SiCoDe(supposedly the best while they were still here) and even those guides\games have problems. I mean, gotoing out of a loop? HELLO??? That was in WAR!! Yeah, the 6 fps game. I optimized it so it no longer does that, and there is virtually no pause when the bomb explodes. Go get it from sicode.ticalc.org if you don't believe me.

Sorry if I'm just wasting space--kill this if you want. Just contact me at harrierfalcon32@yahoo.com

=Clean Up!=

See the conditional page. --Jimmyatic 15:15, 17 April 2007 (UTC)

title: Talk:TI-Basic Z80 Programming/Archive


text:
Aspies Book/How to make my life more predictable

Introduction
The purpose of this chapter is to provide self regulating rules for one to follow, and even kind of "completeness rules". Their purpose is to make your life more stable, and are made with great detail so it will be possible to cope with a problem in a specific and an easy to understand way.

The Social Rules
These are rules for use in social encounters, such as when being approached by someone or chatting online. Some of these rules might not be usable in certain situations, and some may be appropriate only in some cases.

Chatting online

 * When this rule is useful
 * 1) If you want to chat online
 * 2) It will help getting yourself organized if you have bad experiences in a chat room, and you do not wish anymore to chat with people there. In this case these rules might help you communicate in basic way, like greeting, saying goodbye, asking people to be polite, etc.

 * When this rule is not useful
 * 1) The basics of communication are known to many people, and these rules may be seen as very trivial.

The procedure

 * 1) Explanation1 option 1: This section is about sending messages in the public chat room
 * 2) Greeting a person:
 * 3) To greet the person say "hello, nickname-of-person".
 * 4) Expect a reply. If there is no reply from the nickname, then the next step can't be followed.
 * 5) Finding common interests:
 * 6) Say "nickname-of-person, what are your interests?" or "nickname-of-person, what do you find interesting?"
 * 7) After discussing and wishing to learn more about the other person's interests ask "nickname-of-person, do you have any other interest except the one's you told me about?"
 * 8) Explanation1 option 2: This section is about sending messages to a certain nickname.
 * 9) If you do not know if the nickname prefers private messages then send this message to the nickname: "Do you like or dislike private messages?".
 * 10) Greeting the person:
 * 11) To greet the person say "hello".
 * 12) Expect a reply. If you find the reply abusive in any way, then do not continue typing any message to the nickname in private. If there is no reply from the nickname, then the next step can't be followed.
 * 13) Finding common interests:
 * 14) Say "what are your interests?" or "what do you find interesting in your life?"
 * 15) After discussing and wishing to learn more about the other person's interests ask "do you have any other interest except the one's you told me about?"
 * 16) Explanation2:

Handling abuse
Its purpose is to be able to have self control in the chatroom while more than 1 nickname sends you a message that makes you feel abused.

 * When this rule is useful
 * Because when you do not know what to do and feel in an ill mood, then it could be good there were precise instructions on what exactly to do, or what "not to do" while being in this situation.

 * When this rule is not useful
 * It might confuse you, and you might be able to do this spontaneously, without needing the help of these "written rules" (which are different than the so called "unwritten rules")

The procedure
Here is one explanation. If you believe it could be described in an easier way, then add content to the explanation2 section:

 * 1) Explanation 1: Let's say for example that nick1 sends you a message you find abusive and the same does nick2.
 * 2) Say to the channel: "Anyone who wishes to send any complaints of other people can do it through pm. This is a public channel, and there's no reason to use abuse messages"
 * 3) Now you have no right according to this 'rule' to speak to these people in the chatroom, except the "1. Section message" message, which you can send once every 2 minutes.
 * 4) You can use the message "please continue in pm as I said" which you can send as much as you prefer. You can also offer to teach how to send in private messages, because some people might not know how to do it, or might not know how to see incoming private messages.
 * 5) As a next step talk to the nicks in private messages. This is the final step.
 * 6) Explanation 2:

purpose of the rule
These set of actions are about the case that a person starts using swear words against someone or against anything else, and what you should do in that case.

When this rule is useful
If you do not like: ...then the procedures in "Actions or procedures" might help to understand exactly what to do.
 * swear words in the chat room, or
 * abuse messages directed towards somewhere(even yourself), or
 * you do not know towards who the messages are, or
 * you do not like swear words in the public chat room

When this rule is not useful
Nothing known yet

The procedure

 * 1) Explanation1 case 1: more than one user, use words you are feeling uncomfortable with.
 * 2) Say: "[put-nicknames-here-separated-by-space], please stop using swear/abuse words"
 * 3) Explanation2:

7 days of sleep
You can follow this rule if you find it difficult to get enough sleep, without letting yourself get the rest you need.

 * When this rule is useful
 * If you have trouble deciding when you should go to sleep this rule could help with decision making.

 * When this rule is not useful
 * It is not yet complete, or other reason. (add freely)

The procedure

 * 1) Coinsider your circumstances and routine.
 * 2) Decide a precise time to go for sleeping, such as 21:00 or 23:00.
 * 3) It is advised to go for sleeping within the last 15 minutes until the clock shows your selected time. When you wake up, note the time it is somewhere where you can keep stable track of these notes.

Prerequisites

 * 1) To follow this rule you need to know the time you woke up, either by having noted it down or remembered(not recommended) it.
 * 2) You also need to have been awake for no more than 15 hours. If you know when you will be awake for more than 15 hours, then go to sleep before that limit is passed.

Planned computer use
It's for use in the case that you plan to do a certain thing on the computer but end up forgetting it, and then starting surfing the internet or doing unrelated things on the computer continuously and in an unpredictable way.

 * ways to follow the rule
 * 1) rule "Planned computer use 1" close computer followed
 * 2) will follow the rule and at the end close the computer
 * 3) rule "Planned computer use 1" open computer followed
 * 4) will follow the rule and at the end do anything spontaneous that comes to mind at the computer.

The procedure

 * 1) Note down somewhere (on paper, on an electronic device or elsewhere) about what you plan to do on the computer.
 * 2) Also note down if you plan to close the computer afterwards or let yourself do anything spontaneous at it.
 * 3) Next do the steps, and at the end do what you've chosen regarding "ways to follow the rule".


text: TI-Basic 84 Programming

title: TI-Basic 84 Programming


text:
TI-Basic 84 Programming/Introduction

Purpose
The purpose of this book is to teach both the basics and more advanced aspects of the TI-BASIC programming language. Although the book's intention is to instruct newcomers with no previous TI-Basic programming knowledge or experience, those who have some programming experience can use the table of contents to inform themselves on certain aspects of the language, like optimizing code or learning the small yet important differences between certain loop types. Hopefully, the Wiki Community can contribute a vast amount of useful TI-Basic programming knowledge, which will allow this book to provide a much more in-depth look at TI-Basic. Currently, this book only provides information regarding TI-BASIC programming on the TI-83+ or 84+. Of course, the Silver Editions and C or CE versions of the two calculators can be used with this guide.

To learn the language and programming skills in order from beginning to end, the reader should start with this page, the Introduction, and use the links at the bottom of each page to move to the next chapter.

Overview
TI-Basic is a simple programming language used on Texas Instruments (TI) graphing calculators which integrates many normal graphing calculator commands (like storing variables or graphing) into its code.

TI-Basic is a relatively easy language to program in, especially when it is compared with Assembly, the other main language that can be used to program TI graphing calculators. Programs written in TI-Basic, compared to programs written in Assembly, have a small filesize (due to that fact that commands like 'If ' and 'Menu(' use just 1-2 bytes of memory). However, this makes execution of TI-Basic programs very slow, because the calculator first reads through and parses each line of code before translating it into Assembly and executing it (in other words, it suffers from the same performance issues as any interpreted language). Despite its slow speed, the use of TI-Basic is appropriate for many simple programs.

Assumptions
This wikibook assumes that you have at least a partial understanding of the following concepts:
 * What a programming language is
 * Basic algebra
 * Operation of a TI-84 calculator

Versions of TI-BASIC
The two main versions of TI-Basic in use today are TI-BASIC Z80, and TI-BASIC 68K. The "Z80" and "68K" refer to the processor that the calculator uses.

 * TI-Basic Z80 comes on the TI-83, TI-83+, TI-83+ Silver Edition, TI-84+, TI-84+ Silver Edition, TI 84+ C, and TI-84 Plus CE calculators. It is the less powerful version of TI-Basic, but is still fairly versatile.
 * TI-Basic 68K that comes on the TI-89, TI 89 Titanium, TI-92, TI-92 Plus and Voyage 200 calculators. It is the more powerful version of TI-Basic.

It is important to note that these two versions are very different. Z80 syntax is less strict than 68K, but 68K has many useful features like error handling.

title: TI-Basic 84 Programming/Introduction


text:
Talk:Homeopathy/Introduction

NPOV
I have marked this article as NPOV, it states that the doctor who invented it was "something of a genious", that there are "over 3000 remedies proved". Now, the word proved, would indicate the presence of a scientific approach, but the article also states that science "is not advanced enough yet to explain how homeopathy works". It also uses weasel words, saying that "Homeopathy is very widely used". --85.8.2.169 01:11, 2 June 2007 (UTC)

Just removed
I just removed cancer off this list. One, cancer is many diseases not just one disease, so any claim that anything can cure cancer is bull. At best, there are drugs that can cure certain types of cancer, but there is not one drug that can cure all types of cancer. That's just flat wrong. Aids is not quite like cancer, but pretty close, there are different viral strains of AIDS, and no, there is no cure for AIDS yet. While I believe in the free exchange of ideas, I don't believe in leaving bullcrap in Wikibooks. I will declare that I'm a cancer survivor so I have some COI due to my brush with cancer, so I'll edit lightly on this subject from here on out. Necromonger Wekeepwhatwekill 17:24, 27 August 2018 (UTC)
 * Taking a look at this, since two users were back-and-forthing about it, I don't see the grounds for removal. The sentence says absolutely nothing about whether homeopathy works for anything at all; it says that homeopathy is used for a bunch of things, including cancer and AIDS.  The AIDS link is broken, but a look at the link for cancer readily verifies the assertion.  Concerns with the validity of homeopathy don't bear on that particular sentence.  (That said, I notice a few edits a while ago that might usefully be hedged on...) Btw,  there appears to be an extra   in your signature, which was misformatting following text; see the diff on this edit. --Pi zero (discuss • contribs) 21:00, 4 September 2018 (UTC)
 * OK User:Pi zero. I saw your change.  It looks good! Necromonger  Wekeepwhatwekill 21:50, 4 September 2018 (UTC)
 * I hope you're not upset that I've now restored cancer and AIDS to the list of conditions that homeopathy is sometimes applied to. Hopefully the restoration of key passages mitigating claims about homeopathy helps to clarify the status of the list. --Pi zero (discuss • contribs) 23:04, 4 September 2018 (UTC)
 * User:Pi zero I'm okay with the wording since it's clear that it doesn't cure cancer . Thanks for asking ! Necromonger  Wekeepwhatwekill 14:39, 5 September 2018 (UTC)

title: Talk:Homeopathy/Introduction


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title: Template:Stars


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C Sharp Programming/Keywords/override

The keyword is use in declaring an overridden function, which extends a base class function of the same name.

 * Further reading
 * Inheritance keywords

/Keywords

title: C Sharp Programming/Keywords/override


text:
User talk:24.252.205.115

Thanks for experimenting with the page US_History/Contents/Great_Depression_and_New_Deal on Wikibooks. Your test worked, and has been reverted or removed. Please use the sandbox for any other tests you want to do. Take a look at the welcome page if you would like to learn more about contributing to our project. Thanks.

-- SB_Johnny | talk 23:18, 30 April 2007 (UTC)

title: User talk:24.252.205.115


text:
User:Thot~enwikibooks

de:Benutzer:Thot

title: User:Thot~enwikibooks


text:
Autonomous Technology-Assisted Language Learning/Interaction/Text Based

E-mail
Google's free Gmail service has a handy built-in multilingual spelling checker. While composing a message, the writer can click "Check spelling" and Gmail will does its best to auto-detect the language you are writing. Alternatively, you can click the triangle and select the language you are writing from the 32 languages (including Latin!) listed. This feature is not restricted to checking and correcting the spelling in Gmail, as any text can be pasted into a compose window for a quick spelling check.

Bulletin Board Systems
Also referred to as Internet Forums and Message Boards, Web Forums, Message Boards, Discussion Boards, Discussion Groups, or simply, Forums.

 * Yahoo Groups (official website) - Much more than just a passive BB, Yahoo! Groups has space for photos, archived links and files, built-in voice chat (still buggy), poll function, database function (which can be used as a wiki—in all provides a good environment to build an online community.
 * Google Groups (official website)
 * phpBB (official website)
 * See also

Blogs (Weblogs)
In language classrooms, teachers often ask students to use blogs to have asynchronous interaction with their peers and their teachers.
 * Seven things you should know about blogs (pdf)
 * Blogger now lets users create blogs in French
 * For speakers of French, here is more information on creating your own free blog in French.

Wikis
Wikis can be used for asynchronous text interaction with the text, with the author and editors of the text, and with other readers of the text using the "discussion" page. Some activities that L2 learners may find worthwhile are:

 * Write and revise: L2 students can write in their L2 and have their writing corrected by their teachers and/or fellow L2 learners.
 * Read and edit: L2 students can read and edit/correct/revise the text.
 * Read and discuss: L2 students can read and discuss the text with authors and other readers using the "discussion" page that is part of all Mediawiki Wikis.
 * Translate L1 to L2 and/or L2 to L1: L2 students can take an article in the Wikipedia or other wikis and translate from their L1 to L2 and/or from L2 to L1.

BluWiki is a free wiki host that uses MediaWiki software, the same softare used by this Wikibook.

Here is a list of free and paid wiki hosts.

Synchronous Text
My Language Exchange is a site that aids learners of a second language to find each other and communicate in a safe environment through email, chat, and voice chat exchange options.

Instant Messaging (IM)

 * Jabber is "an open, secure, ad-free alternative to consumer IM services like AIM, ICQ, MSN, and Yahoo (see the IM quickstart). Under the hood, Jabber is a set of streaming XML protocols and technologies that enable any two entities on the Internet to exchange messages, presence, and other structured information in close to real time" (from Jabber website). Due to its interoperability with other IM systems, Jabber has great potential for ATALL.
 * Meebo (alhpa version) (official website) is a completely web-based IM client that currently supports a user's accounts on AIM/ICQ, Yahoo! Messenger, Jabber/Google Talk and Microsoft Messenger (MSN). See review.
 * IM Federation (official website)
 * List of instant messengers

Chat Rooms

 * Multilingual
 * Chat rooms in English and other languages (scroll down)
 * Chinese
 * Chinese Chat
 * English
 * English Baby On English baby, users can find English lessons that they can listen to, read the transcriptions, and learn slang and idioms. It is also a platform to find people to practice English. Users can join online chat rooms or to find friends and talk through MSN or other software.

MOOs (MUD Object Oriented)

 * MOOing in a foreign language
 * ActiveWorlds is a web-based virtual reality (VR) space where people interact with one other by moving around various worlds in a three dimensional avatar. The communication is done through text chat. People can create virtual homepages or virtual worlds, where you can interact with the artifacts created in the world. For example, you can teleport through a wormhole to get to different countries, ride virtual roller-coaster rides; visit museums, and buildings. To create your own virtual homepage (or virtual worlds), you need to register and pay a monthly fee. It seems as if used wisely and creatively, it can be a great place to chat in a foreign language. Sadly, only PC users can access the interface.  An Active Worlds site has been established at Michigan State University that can be used for no cost for language learning (contact Professor Young Zhao: zhaoyo@msu.edu).
 * English
 * Tapped In: "Tapped In is the online workplace of an international community of education professionals. K-12 teachers and librarians, professional development staff, teacher education faculty and students, and researchers engage in professional development programs and informal collaborative activities with colleagues."
 * French
 * MOOFrançais
 * Spanish
 * MundoHispano

MMOGs (Massively Multiplayer Online Games)

 * See Purushotma, 2005
 * Yahoo! Games in French You need to have a Yahoo membership to sign in and play a game. Users can select the desired game from the list of options, such as card games, chess, etc. There is the synchronous aspect of the games as players can chat with each other in a Java chat format while playing the game. This may allow for L2 students to learn specific vocabulary pertaining to a game.
 * For other synchronous Yahoo! Games in a desired L2, one can change the country domain in the URL address (i.e. FR for France, DE for Germany, ES for Spain, etc.) to load the games in the desired language. Click on the links below for examples of Yahoo! Games in German and Spanish.
 * Yahoo! Games in German
 * Yahoo! Games in Spanish

Chatterbots (Chatbots)

 * A.L.I.C.E: Alie free online chat
 * DAVE ESL bot (subscription) Dave ESL


text:
Autonomous Technology-Assisted Language Learning/Interaction/Audio with or without Video

E-mail with audio and video

 * mailemotion is a free and easy way to create and send audio/video e-mail.

Voiceboards

 * Gong is free software that provides voice and text message boards. Gong can be used as a stand-alone system, as a Moodle module, or as a "MiniGong" web recorder.
 * Wimba is commercial software that provides voice and text message board.
 * Moodle Forum Moodle, an open-source website structure, includes a forum module that can include attachments. If an audio file is attached to a post, a flash player will automatically appear on the site to play the audio.  This makes it easy for asynchronous conversations that flow in order with replies, pictures of who posted, and structure.

Audioblogs
Like regular blogs, people can use audioblogs to record their life and their thoughts.

A special feature that AudioBlogger has promoted is the capability of recording voice messages in one's audioblog via telephone. One can use any phone they have to call a number that the Audioblogger has provided. However, the telephone number isn't a toll free number.

Audioblog.com is another company that provides audiblog service. Users can use webcam to record their voice and image. And then users can post it on the Audioblog.com. However, this service is not free. The monthly membership fee is $4.95.

Podcasting
Language students can create their own podcasts to be listened to by their teacher and fellow students, as well as by partner (Tandem) teachers and students.

 * Dialcasting is the technique of using a telephone to produce and publish a podcast. The advantage of this approach over other methods for podcasting is that the creator of the voice file doesn't need to be at a computer nor does she need to know how to record audio on a computer.
 * LetsTalk
 * Odeo provides free web-based audio recording, sharing, and listening tools. It is also possible to post audio files via a telephone call, create and manage channels and create and manage podcasts.
 * podOmatic

Free Telephone Service

 * Futurephone Free international telephone calls to over 50 countries via a toll call to Iowa, USA at +1.712.858.8883. May not be charged an Iowa phone call, depending on your specific US telephone plan. Read about it in the following David Pogue blogs from the New York Times. Apparently no longer available.
 * JAJAH Free Global Calling Plan "The JAJAH Free Global Calling Plan applies to land line and mobile calls to and within the United States; Canada; China; Hong Kong; Singapore and Taiwan and it applies to landline calls to and within Australia; UK; Germany; France; Italy and most other European nations. It applies when both call participants are registered JAJAH users. In countries where free phone calls are not available, or if someone is calling a non-JAJAH member, calls are simply subject to JAJAH’s ultra-low rates" (from website)
 * Call China for Free Call China, Hong Kong and Singapore for free (promotional offer)

Broadband Internet Phone Service (VoIP)
Many new and traditional telephone companies now offer unlimited local and long-distance calls (domestic and international) for a fixed monthly fee to customers who have a broadband Internet connection.

As the fees charged are typically much less than traditional phone service, VoIP telephone service can be an economical way for users that already have broadband Internet service to practice their foreign languages with partners in other countries.

For example, for user in the United States, BroadVoice offers unlimited calls to 21 countries for $19.95 a month. For $24.95 subscribers can call 35 countries.

Talk About VoIP.com and Voxilla provide forums and useful information about VoIP service.

Before subscribing to a VoIP telephone service, you might want to make sure first that you can transfer your current telephone number to the VoIP service. You should also check if emergency dialing services (such as 911 in the U.S. and Canada) are available. Also keep in mind that unlike a traditional telephone, VoIP service will not work if your Internet connection is interrupted of if you experience a power failure. For these reasons it is a good idea of have a backup landline or cellular service.

Most traditional telephone companies such as MCI and AT&T in the United States now offer VoIP telephone service.

Here you can find a list of VoIP telephone companies and for comparison.

Computer to Telephone

 * Free World Dialup (FWD)
 * Gizmo Project See below.
 * iConnectHere
 * Skype See below.
 * TalkParade
 * WebPhone
 * 1899.com Free calls to U.K. landline telephones
 * AdCals : Free calls to US and Canada to any home, business or cell phone
 * VoipBuster : Free computer to telephone calls to many countries/
 * Net2Phone : Reportedly works well over busy networks and via dial-up modem.
 * DeltaThree : Reportedly has very good computer-to-telephone performance and good online directory.
 * Applied Language Free Teleconferencing Nationally and Internationally.

Computer to Computer
All of the following programs allow synchronous text communication between Windows-based PCs and/or Apple Macintosh computers connected to the Internet. Most also provide synchronous audio and video communication as well.

For a review of the use of some of these programs for ATALL, see Cziko and Park (2003) pdf html See also New York Times article on PC-to-phone products and developments

 * Skype Advantages of Skype are that it is cross-platform (Windows, Mac, Linux, Pocket PC), has a directory in which users living in selected countries who speak selected  languages can be found, and has a video Skype also has a search function to find other members in desired countries speaking desired languages as well as the ability to search for users to who want to be contacted by other Skype users (Skype me). The disadvantages are that it uses a proprietary protocol, does not interoperate with other communication systems, can use bandwidth from connected computers for other calls, does not indicate when the other party is typing when text chatting, stores text chats on the user's local computer, and does not provide an option for audio recording. Starting in May 2006 and continuing until the end of 2006, Skype offers free  SkypOut calls from computer to any regular or mobile telephone in the U.S. or Canada. For adding audio recording features to Skype, see Skypecasting. PowerGramo is a free program that allows Windows users to record Skype calls.
 * Skype Journal
 * Skype Companion for Language Learners is a program that helps Skype users find partners for language practice. The software is under active development. It's currently only available for Microsoft Windows, although Skype has announced that the Skype API (which this software uses) will soon be available for Linux and Mac OS X.
 * Google Talk . Advantages of Google Talk are its simple interface and use of Jabber (non proprietary) protocol which makes it interoperable with some other instant message systems, shows when the other party is typing in text chat mode, and stores chat sessions on a central server along with the user's Gmail messages under "Chats". Disadvantages are that it does not have conference call capabiility, does not provide video, and does not allow audio for Macintosh users, and uses must have a Gmail account to use Google Talk. (more information)
 * AOL Instant Messenger (AIM) official site
 * DingoTel
 * Dyco Dyco official site
 * Gizmo Project official website The advantages of Gizmo Project are that is uses an open source open protocol (SIP) and therefore is interoperable with other SIP products. It is cross-platform (Windows, Macintosh, Linux). Users can also receive free calls as dialed to one of several regular telephone numbers in the U.S. and U.K. (the caller must pay any normal charges incurred for the call). Conference calls with a large number of participants can be made. There are a large number of SIP telephone networks and university telephone systems that can be called using Gizmo. Gizmo also allows instant message communication with over 10 million Jabber system software users worldwide.
 * IChatAV
 * iVisit [http://www.ivisit.com)
 * MSN Messenger )
 * Windows Live Messenger : beta version; to replace MSN Messenger.There are many advantages to using MSN Live Messenger. First of all it is a completely free program that only takes a downloading. MSN Live Messenger allows people anywhere in the world to interact using synchronous audio or text chatting, with the option of using a webcam. MSN also saves all text chats so people can go back a reference their conversations.
 * PalTalk (official site)
 * PhoneGaim (official website)
 * SightSpeed (official website)
 * VRVS (official site)
 * Windows Messenger (official site)
 * Yahoo Messenger (official site). Yahoo Messenger has the option of joing language specific chat rooms once the program is up and running. The user needs to select the "Messenger" drop window, select "Yahoo Chat," and then select "Join a room." Once the room list has been populated, the user needs to select the "Cultures & Community" folder followed by the sub-folder "By Language." Once this category is visible, it is possible to select a chat room in French, Spanish, Italian to name a few. It is also possible to use video and sound when chatting in the room. It should be mentioned that some of the content in these chat rooms can be of a vulgar nature, so users need to be prepared to hear or read such words/expressions. However, the positive benefits of hearing native speakers and possibly watching them on their webcams (if they allow you to watch them) is a great way to personalize L2 learning.
 * Mercury Messenger (official site)
 * Fire (official site)
 * Gizmo (official site). Unlike the other synchronous voice communications programs listed here, Gizo uses the Session Initiation Protocol (SIP) standard so it can communicate with other voice over IP (VOIP) products.  Like Skype, Gizmo lets you call other Gizmo computer users for free and also lets you call (and receive calls from) regular telephones located anywhere in the world for a per-minute charge (although usually much cheaper than regular long-distance phone calls) For Windows and Macintosh with Linux version promised soon.
 * FreeWorld Dialup (official site).

See also:
 * ViDe Videoconferencing Cookbook
 * Xten X-Lite (official website)
 * Lyceum Voice Groupware
 * Applied Language Free Teleconferencing Nationally and Internationally.

VoIP USB-Telephone Adaptors (USB to RJ11)
VoIP USB-telephone adaptors allow you to connect VoIP systems such as Skype, Google Talk and VoipBuster to your regular telephone system. This allows to do things such as:
 * 1) Use your regular home telephone system to receive and make VoIP calls from your computer.
 * 2) Call your home telephone number from your mobile (cellular) phone to place a call from your computer or to another phone (thus avoiding high mobile-phone international long-distance toll charges)
 * 3) When travelling abroad, you can use a computer VoIP call to connect to your home telephone and call your local calling area, again avoiding international long-distance charges
 * 4) Connect a cordless phone base station to your computer, allowing you to use use your cordless phone to make and receive Voip calls via your computer.

One source of VoIP USB-telephone adaptors in the U.S. is von-phone, offering two models. The AU-600 allows you to record your calls on your computer, but works only with Skpe on Windows. The B2K does not offer call recording, but can be used with both Windows and Linux using Skpe and with Windows using Google Talk, VoipBuster, Net2Phone, X-TenMate and SJPhoneMate for SJPhone.


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Template:LaTeX/Bottom

This template is made to be used at the bottom of each section-page of the LaTeX book.

Usage:  produces a horizontal bar with links to LaTeX/Prevpage and LaTeX/Nextpage, that looks like this:

Either parameter can be empty, in which case that element is omitted from the bar (so that this template can be used on the first and last sections of the book). would look like

while would look like

title: Template:LaTeX/Bottom


text:
Template:LaTeX/Bottom Start

This template is an alternative interface for Template:/Bottom, omitting the first parameter. That is, is equivalent to.

title: Template:LaTeX/Bottom Start


text:
User talk:Jaffelo

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You will find more resources in Community Portal. If you want to ask a question, visit the Study help desk, the Staff lounge, IRC channel or ask me personally on my talk page. For site news, see the Bulletin board. It might be a good idea to add this page to your "watchlist" so that you can see when any new information is posted there. You can do that by clicking the tab labeled "watch" at the top of the page.

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glen I'm a jungle woman! I like to panhandle!

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User talk:Autie62~enwikibooks

Edits to Free ABA
Wow great additions to [Free_ABA_Basics]! Thanks and keep up the work. I hope you don't mind that I added some minor formatting changes using wiki syntax. Harriska2 14:37, 1 May 2007 (UTC)

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The developer team at Wikimedia is making some changes to how accounts work, as part of our on-going efforts to provide new and better tools for our users like cross-wiki notifications. These changes will mean you have the same account name everywhere. This will let us give you new features that will help you edit and discuss better, and allow more flexible user permissions for tools. One of the side-effects of this is that user accounts will now have to be unique across all 900 Wikimedia wikis. See the announcement for more information.

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text:
TI-Basic 84 Programming/Book Conventions

Conventions
A number of conventions are used in this book. Learning these conventions will aid in the learning process.

As this is a book designed to teach one how to program TI-Basic programs, there will be several pieces of code throughout the chapter. Thus, special boxes have been designed so that one can easily find where certain portions of code exist.

There are three main code boxes: Syntax, Examples, and Output.

Syntax
Syntax is the way a command must be stated. For example, the output function has certain restrictions. There must first be a Y coordinate, an X coordinate, and then what is to be outputted. To inform one of all these restrictions, this book would display them in the following fashion:

Examples
Examples are just that, Examples. They are examples of the commands in use, sometimes only containing one command, sometimes containing more. Often there are more than one example for a given function, with different variations in the way the command can be used. Examples are formatted as follows

The previous example will always display HELLO WORLD.

Usually, but not always, there will be some sort of explanation either before or after the example.

Output
Output is merely used to show one how certain programs or functions would look on the calculator. If there is an example prior to the Output box, it is implied that the program was executed from the homescreen, but that the program name is not present (i.e. there is no pgrmPROGRAM display for each output). Outputs are displayed as follows:

Code
It should be noted that the calculator screen can only show a certain amount of characters (16 characters monochrome calculators, and 22 characters for color calculators). This constraint is ignored in this book. In other words, while the code would be like this on the calculator:

It is still written this way in this guide:

Commands
It must be understood that to "type" commands (commands are all code other than strings and mathematical functions) like Disp for example, are not written by typing each character (D then i then s then p), but rather by accessing the token <tt>Disp</tt> in one of the menus built into the calculator. Most instructions are only found in certain menus.

The <tt>Disp</tt> instruction, for example, can be found by pressing PRGM, then moving to the I/O menu, and then either pressing 3 or scrolling down to it and pressing <tt>Enter</tt>. Each keypress, in order. ((NOTE: This assumes you are already in the Program Editor, this makes a big difference))

In this book, in order to shorten the commands, the above would be shown as PRGM:I/O:3.

These are the exact keys that are pressed in order to access the command, separated by a colon ':'. If a command is accessed by pressing the second key, the menu has the menu name listed first, then the actual key text listed in parenthesis.

So, in order to find <tt>Pxl-On(</tt>, the instructions would be 2nd:DRAW(PRGM):POINTS:5. the 2nd key is pressed, followed by the DRAW menu (which is really the secondary PRGM), then one navigates to POINTS, then presses 5 or finds the function <tt>Pxl-On(</tt>, on the list.

It should also be noted that most instructions can also be accessed through the Catalog, 2nd:CATALOG(0).


text:
IB Physics/Mechanics

Return to IB Physics

Topic 2: Mechanics

Kinematic concepts
2.1.1 Define displacement, velocity, speed and acceleration.

 * Vector quantities always have a direction associated with them.

2.1.2 Define and explain the difference between instantaneous and average values of speed, velocity and acceleration.

 * Average value - over a period of time.

 * Instantaneous value - at one particular time.

2.1.3 Outline the conditions under which the equations for uniformly accelerated motion may be applied.

Acceleration must be constant

Graphical representation of motion
2.1.4 Draw and analyse distance–time graphs, displacement–time graphs, velocity–time graphs and acceleration–time graphs.

2.1.5 ''Analyse and calculate the slopes of displacement–time graphs and velocity – time graphs, and the areas under velocity–time graphs and acceleration–time graphs. Relate these to the relevant kinematic quantity.''

Uniformly accelerated motion
Determine the velocity and acceleration from simple timing situations

$$ \begin{align} &\left[\vec{a}=\dfrac{\vec{v}-\vec{u}}{t}\right] && \left[\vec{s}=\dfrac{(\vec{u}+\vec{v})t}{2}\right] &&& \left[\vec{s}=\vec{u}t+\dfrac{1}{2}\vec{a}t^2\right] &&&& \left[\vec{v}^2=\vec{u}^2+2\vec{a}\vec{s}\right]. \\ \end{align} $$

Derive the equations for uniformly accelerated motion.

There are three equations for uniformly accelerated motion. The first one is derived form the definition of acceleration as the rate of change of velocity,

i.e

$$ \text{acceleration}=\vec{a}=\dfrac{\partial}{\partial t}\,\vec{v}=\dfrac{\text{change in velocity}}{\text{change in time}}. $$

Let the initial and final velocities be designated by $$u$$ and $$v$$ respectively, acceleration by $$a$$ and time by $$t$$, then

$$ \vec{a}=\dfrac{\vec{v}-\vec{u}}{t}. $$

Making v the subject we get,

$$ \vec{v}=\vec{u}+\vec{a}t, $$

which is the first equation of motion.

Describe the vertical motion of an object in a uniform gravitational field.

Describe the effects of air resistance on falling objects.

Solve problems involving uniformly accelerated motion.

Forces and free-body diagrams
Identify the forces acting on an object and draw free-body diagrams representing the forces acting. Each force should be labelled by name or given a commonly accepted symbol. Vectors should have lengths approximately proportional to their magnitudes.

Newton’s first law
Newton's First Law of Motion states that a body will remain at rest or moving with a constant velocity unless acted upon by an unbalanced force.

Equilibrium
Equilibrium is the condition of a system in which competing influences (such as forces) are balanced.

Newton’s second law
$$ \sum \vec{F}=m\vec{a}. $$

Alternately:

$$ \sum \vec{F}=\dfrac{\partial}{\partial t}\,\vec{p}=\dfrac{\text{change in momentum}}{\text{change in time}}. $$

In words, the resultant force is all that matters in the second law. The direction of motion depends on the direction of the resultant force.

Newton’s third law
If body A exerts a force on body B, then body B exerts an equal and opposite force on body A along the line of centers.

Every action force has an equal and opposite reaction force. This is why you are able to place your coffee mug on the table without it falling into the table. The table provides a normal reaction force (up) to counter the gravitational force (down) hence F(net) = 0 and your coffee mug stays on the table. Important to note is that the opposite reaction must happen along the lines of centers, i.e, the vector arrow of the opposite force must be aimed at the first force while still being opposite.

Inertial Mass, Gravitational Mass and Weight (2.3)
An object's inertial mass is defined as the ratio of the applied force $$\vec{F}$$, to its acceleration, $$\vec{a}$$, where $$\vec{F}$$ and $$\vec{a}$$ are no higher than one dimensional vectors, given that vector division is not well defined beyond one dimension.

$$m_{inertial}=\dfrac{\vec{F}}{\vec{a}}$$

State Newton's first law of motion (2.2.4)
In ancient times, Aristotle had maintained that a force is what is required to keep a body in motion. The higher the speed, the larger the force needed. Aristotle's idea of force is not unreasonable and is in fact in accordance with experience from everyday life: It does require a force to push a piece of furniture from one corner of a room to another. What Aristotle failed to appreciate is that everyday life is plagued by friction. An object in motion comes to rest because of friction and thus a force is required if it is to keep moving. This force is needed in order to cancel the force of friction that opposes the motion. In an idealized world with no friction, a body that is set into motion does not require a force to keep it moving. Galileo, 2000 years after Aristotle, was the first to realize that the state of no motion and the state of motion with constant speed in a straight line are indistinguishable from each other. Since no force is present in the case of no motion, no forces are required in the case of motion in a straight line with constant speed either. Force is related to changes in velocity (i.e. acceleration)

Newton's first law (generalizing Galileo's statements) states the following:

When no forces act on a body, that body will either remain at rest or continue to move along a straight line at constant speed.

A body that moves with acceleration (i.e. changing speed or changing direction of motion) must have a force acting on it. An ice hockey puck slides on ice with practically no friction and will thus move with constant speed in a straight line. A spacecraft leaving the solar system with its engines off has no force acting on it and will continue to move in a straight line at constant speed (until it encounters another body that will attract or hit it). Using the first law, it is easy to see if a force is acting on a body. For example, the earth rotates around the sun and thus we know at once that a force must be acting on the Earth.

Newton's first law is also called the law of Inertia

Inertia is the reluctance of a body to change its state of motion. Inertia keeps the body in the same state of motion when no forces act on the body. When a car accelerates forward, the passengers are thrown back into their seats. If a car brakes abruptly, the passengers are thrown forward. This implies that a mass tends to stay in the state of motion it was in before the force acted on it. The reaction of a body to a change in its state of motion is inertia.

A well-known example of inertia is that of a magician who very suddenly pulls the tablecloth off a table leaving all the plates, glasses, etc., behind on the table. The inertia of these objects make them 'want' to stay on the table where they are. Similarly, if you pull very suddenly on a roll of toilet papers you will tear off a sheet. But if you pull gently you will only succeed in making the paper roll rotate.

Work
Work refers to an activity involving a force and movement along the direction of the force. It is a scalar quantity that is measured in Joules (Newton meters in SI units) which can be defined as:

$$ W=\vec{F}\cdot \vec{s}\,\text{cos}(\theta) $$

Where $$\vec{F}$$ is the force applied to the object, $$\vec{s}$$ is the displacement of the object and $$\text{cos}(\theta)$$ is the cosine of the angle between the force and the displacement, and where $$\cdot$$ is the dot product.

In a linear example (with the force being exerted in the same direction as the displacement), the $$\text{cos}(\theta)$$ is equal to $$1$$ and the equation simplifies to $$W=\vec{F}\cdot \vec{s}$$.

Example calculation:

If a force of $$20$$ newtons pushes an object $$5$$ meters in the same direction as the force what is the work done?

$$ \begin{align} &F=20\,\text{N}\\ &s=5\,\text{m} \\ &W=\vec{F}\cdot \vec{s}=20\times 5=100\,\text{J} \\ \end{align} $$

Answer: $$100$$ Joules of work is done.

Examples (when is work done?): Force making an object move faster (accelerating) Lifting an object up (moving it to a higher position in the gravitational field) Compressing a spring

When is work not done?: When there is no force Object moving at a constant speed Object not moving

Some useful equations;

If an object is being lifted vertically the work done to it can be calculated using the equation

$$ W=m\,g\,h $$

Where $$m$$ is the mass in kilograms, $$g$$ is the earth's gravitational field strength ($$10\;N\,kg^{-1}$$), and $$h$$ is the height in meters.

Work done in compressing or extending a spring:

$$ W=\dfrac{1}{2}\,k\,\vec{s}^2 $$

Where $$k$$ is Hooke's constant and $$\vec{s}$$ is the displacement.

Energy and Power
Energy is the capacity for doing work. The amount of energy you transfer is equal to the work done. Energy is a measure of the amount of work done, this means that the units for energy and work must be the same- joules. Energy is like the "currency" for performing work. To do $$100$$ joules of work, you must expend $$100$$ joules of energy.

Conservation of energy

In any situation the change in energy must be accounted for. If it is 'lost' by one object it must be gained by another. This is the principle of conservation of energy which can be stated in several ways:

 * The total overall energy of a closed system must be constant
 * Energy is neither created or destroyed, it just changes form.
 * there is no change in the total energy of the universe

Energy can be in many different types these include:

 * Kinetic energy, Gravitational potential energy, Elastic potential energy, Electrostatic potential energy, Thermal energy, Electrical energy, Chemical energy, Nuclear energy, Internal energy, Radiant energy, Solar energy, and light energy.

You will need equations for the first three
 * $$\text{Kinetic energy}=E_{K}=\dfrac{1}{2}\,m\vec{v}^2$$ where $$m$$ is the mass in $$\text{kg}$$, $$v$$ is the velocity (in $$m\,s^{-1}$$)
 * $$\text{Gravitational potential energy}=E_{p}=mg\Delta h$$ where $$m$$ is the mass in $$\text{kg}$$, $$g$$ is the gravitational field strength, and $$\Delta h$$ is the change in height.
 * $$\text{Elastic potential energy}=E_{p}=\dfrac{1}{2}\,k\,\left(\Delta x\right)^2$$ where k is the spring constant and $$\Delta x$$ is the extension.

Power - measured in Watts ($$\text{W}$$) or Joules per second ($$\text{J}\,\text{s}^{-1}$$)- is the rate of doing work or the rate at which energy is transferred.

$$ \text{Power}=P=\dfrac{\text{energy transferred}}{\text{time taken}}=\dfrac{E}{t}. $$

If something is moving at a constant velocity $$v$$ against a constant frictional force $$\vec{f}$$, the power $$P$$ needed is $$P=\vec{f}\cdot \vec{v}$$.

If you do $$100$$ joules of work in one second (using $$100$$ joules of energy), the power is $$100$$ watts.

Efficiency is the ratio of useful energy to the total energy transferred.

Work-Energy Principle
The change in the kinetic energy of an object is equal to the net work done on the object.

$$ W_{net}=\dfrac{1}{2}mv_{final}^2-\dfrac{1}{2}mv_{initial}^2 $$

This fact is referred to as the Work-Energy Principle and is often a very useful tool in mechanics problem solving. It is derivable from conservation of energy and the application of the relationships for work and energy, so it is not independent of the conservation laws. It is in fact a specific application of conservation of energy. However, there are so many mechanical problems which are solved efficiently by applying this principle that it merits separate attention as a working principle.

For a straight-line collision, the net work done is equal to the average force of impact times the distance traveled during the impact:

$$ W_{net}=\vec{F}_{avg}\cdot \vec{s}. $$

$$ \text{Average impact force}\cdot \text{distance traveled}=\vec{F}_{avg}\,d=\dfrac{1}{2}\,m\vec{v}^2=\text{change in kinetic energy} $$

If a moving object is stopped by a collision, extending the stopping distance will reduce the average impact force.

Uniform Circular Motion (2.6)
The centripetal force with constant speed  $$v$$, at a distance $$R$$ from the center is defined as:

$$F = m\dfrac{v^2}{R}$$

title: IB Physics/Mechanics


text: Understanding C++

title: Understanding C++


text:
Understanding C++/Introduction

Introduction
To understand the natives, you must learn their language.

A software program or application consists of a sequence of instructions that tells a computer what to do. A cake recipe can be thought of as a program with a list of instructions that tells a person what to do to make a cake. You can refer to the same cake recipe anytime you wish to make a cake when you know the language the instructions are written in. A computer can refer to the same software program to repeat the same sequence of instructions again later when the instructions are within the set of instructions the computer can follow. The set of instructions a computer can follow is known as an instruction set.

An instruction may need to receive input for a computer to do something, process the input as data, and return information as output. The output of one instruction may be used as the input of another instruction. Input and output may be anything the computer is designed to do. A cake making computer might need to know how many servings to make as input, inform you of how much of each ingredient is needed as output, and process the ingredients to make cake.

A programming language consists of the set of available instructions that can be used to tell a computer what to do and grammatical rules that when followed can be used to create meaningful expressions, such as "1+1". The English language has grammatical rules that when followed can be used to create meaningful sentences from different types of words, like nouns and verbs. rules Language when grammar sense followed make are (Languages make sense when grammar rules are followed). The importance of proper grammar should be clear.

An expression is a sequence of one or more grammatically correct instructions that tell a computer what to do. A compiler is a software program that translates the meaning of expressions of a programming language into appropriate instructions for a computer. Anyone who understands how to write expressions of a programming language can tell a computer what to do by using a compiler to do the translation, much like a person who knows both Spanish and English can be a translator for people who only know English or Spanish. A person who understands and can use a programming language to write software programs is called a programmer.

An electronic calculator is one of the simplest forms of a computer with expressions consisting of numbers, mathematical operators and functions like log that can be combined together to a create mathematical expression that the calculator can process to return a result. The mathematical expression "1+1", for example, consists of the instruction add which takes as input two numbers and when processed by the calculator returns "2" as the result or output. However unlike calculators, the instructions of one computer may not mean anything to another computer, just as two people who don't share a common language may not understand each other. Programming languages, like C++, make writing portable programs easier, through translation of a consistent language into instructions that the target computer can process.

Expressions in C++ consist of numbers, operators, variables, functions, classes, enumerations and other things which make up the language. In English, various punctuation marks end a sentence. In C++, a semicolon (;) ends all statements, such as "a=1+1;". A block is a group of statements surrounded by open and closing curly brackets ({}). Blocks serve much the same purpose as paragraphs do in English.

Example program
Now that you understand the basic building blocks of C++, you are ready to see your first C++ program:

You have probably seen some things that don't make sense yet. Let's look at this, piece by piece.

Lines 1 through 6 denote a C++ comment. Comments help those reviewing code and are completely ignored by compilers. Comments are often used for record keeping purposes, or to cause a section of code to be ignored by compilers. Similar to blocks described above, "/*" begins a comment block, and the first occurrence of "*/" ends a comment block.

Line 8 is the first instruction that compilers will not ignore, it reads "#include <iostream>". #include tells the compiler to consider the content of a file to be part of the current program. In the case of iostream, a C++ program will be able to receive input and send output. Inclusion makes programming in C++ easier by allowing you to reuse other programmer's existing work in your own program.

Line 10, you will find more key term(s) in C++. int is one of the basic types in C++. int is short for integer. An <tt>int</tt> can hold any whole number value, positive or negative, within certain limits, but we won't get to that for a while.

Next you will find <tt>main</tt>, a function name. C++ programs begin by calling the <tt>main</tt> function. C++ programs must have only one main function and that function must return an integer.

Next you will find <tt></tt>, which means this function isn't passed anything. We will talk about functions later.

Next is <tt>{</tt>, which indicates the beginning of a block. This particular block is called a function block. We will discuss other types of blocks that exist in C++ later as new concepts are introduced.

Before continuing, meet "using namespace std;". This expression means that std:: doesn't need to be included before certain things in the standard library. This can save typing, but at a cost which we'll get to later. After including that the code can be shortened like this:

Next, "what are those weird << things doing in the code?" you may ask. This tells the compiler "Ok, this is what we are going to print to the screen." and when you see something like:

'''cout << "Hello World!" << endl << "My name is Dell!" << endl;'''

You may wonder why not just do this?:

'''cout "Hello World!" endl "My name is Dell!";'''

The reason is syntax. Without the << in place, the compiler doesn't know when to perform the next task (which in this case, the 2nd task is the "Hello World!"). Technically, this is what the computer thinks (you don't have to read it if you understand):

"Ok, i see a cout. That means print stuff to the prompt. Next to it i see "Hello World!", ill send that to the screen. Oh, i see a <<, im moving on to the next step. The next thing is endl, so i will create a new line. Another <<! Wow, i need to play the lotto. Ok, so now i have to print "My name is Dell!". Now i see ;. Ok, im done with this whole line of code."

Now, the basis in which programming interactive programs... variables. In short, variables store stuff, as in a storage bin. This will be finished later...

Throughout the rest of this book, you will learn more about C++, the standard rules of the language, and come to understand this and other C++ programs you may encounter. The rest of this chapter takes a look at what each of the remaining chapters in this book covers.

title: Understanding C++/Introduction


text:
User talk:82.44.168.39

You are removing significant content from Wikibooks without explanation. Please explain here or in the edit summaries. Your changes will be reverted otherwise - thanks -- Herby talk thyme 16:44, 1 May 2007 (UTC)

Thanks for experimenting with Wikibooks. Your test worked, and has now been removed. Please use Sandbox for any other tests you want to do, since testing material in modules will normally be removed quickly. Please see the welcome page if you would like to learn more about contributing to our project. Thanks. -- Herby talk thyme 17:50, 1 May 2007 (UTC)

Welcome to Wikibooks. We invite everyone to contribute constructively to our collection. Take a look at the welcome page if you would like to learn more about contributing. However, unconstructive edits are considered vandalism, and if you continue in this manner you may be blocked from editing without further warning. Please stop, and consider improving rather than damaging the hard work of others. Thanks. -- Herby talk thyme 12:51, 2 May 2007 (UTC)

title: User talk:82.44.168.39


text: Category:Book:Understanding C++

title: Category:Book:Understanding C++


text:
User talk:Mo Anabre

hello Mo Anabre, welcome to wikibooks! I saw your reply to my comment at the limits page. I'm not a complete idiot but I do tend to oversimplify, so thank you for the clarification.

We could always use more authors in the field of mathematics, so if you are interested in editing and contributing more, it would be a big benefit. If you have any questions about wikibooks, you can ask me on my user talk page. --Whiteknight (talk) 17:47, 1 May 2007 (UTC)

title: User talk:Mo Anabre


text:
User talk:204.81.7.14

Thanks for experimenting with Wikibooks. Your test worked, and has now been removed. Please use Sandbox for any other tests you want to do, since testing material in modules will normally be removed quickly. Please see the welcome page if you would like to learn more about contributing to our project. Thanks. -- Herby talk thyme 17:51, 1 May 2007 (UTC)

title: User talk:204.81.7.14


text:
Microprocessor Design/Virtual Memory

Virtual Memory is a computer concept where the main memory is broken up into a series of individual pages. Those pages can be moved in memory as a unit, or they can even be moved to secondary storage to make room in main memory for new data. In essence, virtual memory allows a computer to use more RAM than it has available.

If a simple virtual==physical address path is adequate for your CPU, you don't need virtual memory.

Most processors have a very simple address path -- address bits come from the PC or some other programmer-visible register, or directly from some instruction, and they are directly applied to the address bus.

Many general-purpose processors have a more complex address path: user-level programs run as if they have a simple address path, but the physical address applied to the address bus is significantly different than the programmer-visible address. This enables virtual memory, memory protection, and other desirable features.

If your CPU needs to do this, then you need something to translate user-visible addresses to physical address -- either design the CPU to connect to some off-chip bank register or MMU (such as the 8722 MMU or the 68851 MMU) or design in an on-chip bank register or MMU.

You may want to do this in order to:
 * support various debug tools that trap on reads or writes to selected addresses.
 * allow access to more RAM (wider physical address) than the user-level address seems to support (banking)
 * support many different programs all in RAM at the same time at different physical RAM locations, even though they were all compiled to run at location 0x300.
 * allow a program to successfully read and write a large block of data using normal LOAD and STORE instructions as if it were all in RAM, even though the machine doesn't have that much RAM (paging with virtual memory)
 * support a "protected" supervisor-level system that can run buggy or malicious user-level code in an isolated sandbox at full speed without damaging other user-level programs or the supervisor system itself -- Popek and Goldberg virtualization, W xor X memory protection, etc.
 * or some combination of the above.

Implementation
Virtual memory can be implemented both in hardware and (to a lesser degree) in software, although many modern implementations have both hard and soft components. We discuss virtual memory here because many modern PC and server processors have virtual memory capabilities built in.

Paging systems are designed to be transparent, that is, the (user-mode) programs running on the microprocessor do not need to be explicitly aware of the paging mechanism to operate correctly.

Many processor systems give pages certain qualifiers to specify what kinds of data can be stored in the page. For instance, many new processors specify whether a page contains instructions or data, so that data pages cannot be executed as instructions, and instructions cannot be corrupted by data writes (see W^X).

The hardware part of virtual memory is called the memory management unit (MMU). Most MMUs have a granularity of one page.

A few CPU designs use a more fine-grained access control to detect and prevent buffer overflow bugs, a common security vulnerability.

Memory Accessing
Memory addresses correspond to a particular page, and an offset within that page. If a page is 212 bytes in a 32-bit computer, then the first 20 bits of the memory address are the page address, and the lower 12 bits are the offset of the data inside that page. The top 20 bits in this case will be separated from the address, and they will be replaced with the current physical address of that page. If the page does not exist in main memory, the processor (or the paging software) will retrieve the page from secondary storage, which can cause a significant delay.

Pages
A page is a basic unit of memory, typically several kilobytes or larger. A page may be moved in memory to different locations, or if it is not being used, it can frequently be moved to secondary storage instead. The area in the secondary storage is typically known as the page file, the "scratchpad", or something similar.

Page Table
The addresses of the various pages are stored in a paging table. The paging table itself can be stored in a memory unit inside the processor, or it can reside in a dedicated area of main memory.

Page Faults
A page fault occurs when the processor cannot find a page in the page table.

Translation Look-Aside Buffer
The translation look-aside buffer (TLB) is a small structure, similar to a cache, that stores the addresses of the most recently used pages. Looking up a page in the TLB is much faster than searching for the page in the page table. When the processor cannot find a particular page in the TLB, it is known as a "TLB Miss". When the TLB misses, the processor looks for the page in the page table. If the page is not in the table either, there is a page fault.

Notice that even though the TLB can be considered a kind of cache, caching part of the page table stored in main memory, it is a physically separate structure than the instruction cache or the data cache, and has several features not found in those caches.

TLB entry
The SRAM in the TLB can be seen as entirely composed of TLB entries. The format of the TLB entries in the TLB SRAM is fixed by the TLB hardware. The paging supervisor -- part of the operating system -- typically maintains a page table in main memory which stores the page table entries in exactly the same format as TLB entries. Each TLB entry contains:
 * the virtual address of a page (analogous to the "tag" in a cache)
 * the physical address of a page (analogous to the "data" in a cache)

While not essential, some TLB hardware has many other optional control and protection fields and flags in the TLB, including:
 * the no-execute bit (NX bit), used to implement W^X ("Write XOR Execute")
 * a "dirty bit" (also called the "modified bit"), set whenever there is a STORE written into that page, and typically cleared when the modified page is written to the backing store.
 * the writable bit, used to implement PaX, sometimes cleared and later set by the OS in order to implement copy-on-write (COW)
 * which virtual address space a physical page belongs to (unnecessary on a single address space operating system)
 * the supervisor bit
 * statistics on which TLB entries were most recently or most frequently used, used to decide which TLB entry to discard when loading a new TLB entry from main memory
 * statistics on which page was most recently or most frequently used, used to support LRU or more sophisticated page-replacement algorithms that decide which page currently in main memory to "page out" to the backing store when the OS needs to load some other page from the backing store into physical memory

The page table entries may include additional per-page fields that are not copied into the TLB entries, such as
 * the "pinned bit" (aka "fixed flag") that indicates that a page must stay in main memory -- the paging supervisor marks as pinned pages that must stay in main memory, including the paging supervisor executable code itself, the device drivers for the secondary storage devices on which pages are swapped out; interrupt handler executable code. Some data buffers are also pinned during I/O transactions during the time that devices outside the CPU read or write those buffers (direct memory access and I/O channel hardware).
 * a "present" bit (clear when that particular virtual page does not currently exist in physical main memory)

title: Microprocessor Design/Virtual Memory


text:
User:Majorly

I am Majorly @ Meta

I am mostly doing gnome type work here, as a break from Meta-wiki. When I am more "settled" I may start a new book from scratch, but that is very unlikely! Otherwise, it's mostly typo fixing, copyediting and generally improving the stuff already here. Happy reading!

title: User:Majorly


text:
User talk:Majorly

Hello, and welcome to Wikibooks!

Here are some tips to help you get started:
 * To learn the wiki-markup-language syntax, see Help:Editing.
 * You should sign your name on Talk and vote pages using four tildes, like this: ~~~~
 * There is a box at the top of the edit window that will insert this, too; it looks like part of a signature.
 * Remember to conduct any editing experiments in the sandbox.
 * You can tell the community something about yourself in your userpage.
 * You can get to this page by clicking the tab at the top of the page labeled with your registered username.
 * If you are a Wikipedian, see Wikibooks for Wikipedians for a primer on how things work here (it's a little different).
 * If you want to base your work here on materials from Wikipedia, please use WB:RFI (requests for importation) to bring the material over in compliance with the GFDL.
 * If you're an instructor and plan on using Wikibooks for a class project, see Guidelines for class projects
 * Please say hello at the Staff Lounge with any questions or ideas.
 * Eventually, you might want to read the Manual of Style and Policies and Guidelines.
 * Please take a look at Naming policy before starting a new book.
 * Remember to maintain a Neutral point of view.
 * Explore, be bold in editing pages, and have fun!

You will find more resources in Community Portal. If you want to ask a question, visit the Study help desk, the Staff lounge, IRC channel or ask me personally on my talk page. For site news, see the Bulletin board. It might be a good idea to add this page to your "watchlist" so that you can see when any new information is posted there. You can do that by clicking the tab labeled "watch" at the top of the page.

Good luck!  -- Herby talk thyme 19:00, 1 May 2007 (UTC)

Hi there
Just to let you know there are some familiar faces here. – Mike.lifeguard  | talk 00:36, 31 January 2008 (UTC)
 * Also, do you miss rollback? Admins can hand it out here, so you can request it if you like. – Mike.lifeguard  | talk 00:38, 31 January 2008 (UTC)

Gadgets
You may like to check out the .js gadgets here (in preferences). There is a neat "warn" as well as "welcome". Cheers -- Herby talk thyme 12:26, 31 January 2008 (UTC)

re-naming a page
Hi, i search the instructions etc, but i couldn't find it...

How do i rename a page? I am writing a user manual for a software. Name is eac3to, but wiki automatically created a page with first letter upper case (Eac3to) which isn't preferred.

Thank you.

title: User talk:Majorly


text: Template:Goodbook/Introduction to Sociology


text: Template:Goodbook/Knowing Knoppix

title: Template:Goodbook/Knowing Knoppix


text: Template:Goodbook/LaTeX

title: Template:Goodbook/LaTeX


text: Template:Goodbook/Physics Study Guide

title: Template:Goodbook/Physics Study Guide


text: Template:Goodbook/How To Assemble A Desktop PC


text: Template:Goodbook/Managing Groups and Teams


text: Template:Goodbook/High School Mathematics Extensions


text:
User:Ben Mills/Sandpit

Ideal gas
$$ pV = nRT \,\!$$

van der Waals' equation
$$p = \frac{nRT}{V-nb} - a \left ( \frac{n}{V} \right )^2 $$

Electron configs
$$1\mbox{s}^2 2\mbox{s}^2 2\mbox{p}^6 3\mbox{s}^2 3\mbox{p}^6 3\mbox{d}^{10} 4\mbox{s}^2 4\mbox{p}^6 4\mbox{d}^{10} 4\mbox{f}^{14} \,\!$$

$$1\mbox{s}^2 \, 2\mbox{s}^2 \, 2\mbox{p}^6 \, 3\mbox{s}^2 \, 3\mbox{p}^6 \, 3\mbox{d}^{10} \, 4\mbox{s}^2 \, 4\mbox{p}^6 \, 4\mbox{d}^{10} \, 4\mbox{f}^{14} \,\!$$

$$[\mbox{He}] \, 2\mbox{s}^2 \, 2\mbox{p}_x^2 \, 2\mbox{p}_y^2 \, 2\mbox{p}_z^2 \, 3\mbox{s}^2 \, 3\mbox{p}^6 \, 3\mbox{d}_{z^2}^{2} \, 3\mbox{d}_{x^2-y^2}^{2} \, 3\mbox{d}_{xy}^{2} \, 3\mbox{d}_{xz}^{2} \, 3\mbox{d}_{yz}^{2} \,\!$$

$$\mbox{p}^6 = \mbox{p}_x^2 \quad \mbox{p}_y^2 \quad \mbox{p}_z^2 \,\!$$

$$\mbox{d}^{10} = \mbox{d}_{z^2}^{2} \quad \mbox{d}_{x^2-y^2}^{2} \quad \mbox{d}_{xy}^{2} \quad \mbox{d}_{xz}^{2} \quad \mbox{d}_{yz}^{2} \,\!$$

Reactions of acids with bases
acid + base → salt + water

AH + BOH → AB + H2O

HCl + NaOH → NaCl + H2O

$$ a\mbox{H}_b\mbox{X} + b\mbox{M(OH)}_a \to \mbox{M}_b\mbox{X}_a + \mbox{H}_2\mbox{O} \,\!$$

Reactions of acids with metals
acid + metal → salt + hydrogen

2AH + 2M → 2MA + H2

2HCl + 2Na → 2NaCl + H2

2AH + M → MA2 + H2

2HCl + Mg → MgCl2 + H2

6AH + 2M → 2MA3 + 3H2

6HCl + 2Al → 2AlCl3 + 3H2

For any acid, HbX, and any metal, M, with valency a, the stoichiometry of the metal-acid reaction is as follows:

$$ a\mbox{H}_b\mbox{X} + b\mbox{M} \to \mbox{M}_b\mbox{X}_a + \frac{ab}{2}\mbox{H}_2 \,\!$$

Reactions of acids with carbonates
acid + carbonate → salt + water + carbon dioxide

2AH + M2CO3 → 2MA + H2O + CO2

2HCl + Na2CO3 → 2NaCl + H2O + CO2

2AH + MCO3 → MA2 + H2O + CO2

2HCl + CaCO3 → CaCl2 + H2O + CO2

$$ \frac{2}{b}\mbox{H}_b\mbox{X} + \mbox{M}_{\frac{2}{a}}\mbox{CO}_3 \to \mbox{MX}_{\frac{a}{b}} + \mbox{CO}_2 + \mbox{H}_2\mbox{O} \,\!$$

Precipitation reactions
$$ b\mbox{M}^{a+}\mbox{(aq)} + a\mbox{X}^{b-}\mbox{(aq)} \to \mbox{M}_b\mbox{X}_a\mbox{(s)} \,\!$$

Quantum mechanics
$$ \hat{H} \psi = E \psi \,\!$$

$$ \hat{H} = -\frac{ \hbar^2 }{ 2m_e } \nabla^2 - \frac{ e^2 }{ 4\pi \epsilon_0 r } \,\!$$

$$ \nabla^2 = \left ( \frac{ \partial^2 }{ \partial x^2 } + \frac{ \partial^2 }{ \partial y^2 } + \frac{ \partial^2 }{ \partial z^2 } \right ) \,\!$$

Schrödinger equation for a one-electron system
$$ \psi_{n,l,m}(x,y,z) \,\!$$

$$ E_n = -R_h\frac{Z^2}{n^2} \,\!$$

$$ R_h = \frac{m_e e^4}{8 \epsilon_0^2 h^2} \,\!$$

GCSE maths
$$ x^a \times x^b = x^{a+b} \,\!$$

$$ \frac{x^a}{x^b} = x^{a-b} \,\!$$

$$ (x^a)^b = x^{ab} \,\!$$

$$ x^{-1} = \frac{1}{x} \,\!$$

$$ x^{-n} = \frac{1}{x^n} \,\!$$

$$ x^{\frac{1}{2}} = \sqrt{x} \,\!$$

$$ x^{\frac{1}{n}} = \sqrt[n]{x} \,\!$$

$$ x^{-\frac{1}{n}} = \frac{1}{\sqrt[n]{x}} \,\!$$

Thermodynamics
$$ S = k \ln w \,\!$$

$$ \Delta G = \Delta H - T \Delta S \,\!$$

$$ \Delta G = -RT \ln{K} \,\!$$

$$ C_p = \left ( \frac{\partial H}{\partial T} \right )_p $$

$$ C_V = \left ( \frac{\partial U}{\partial T} \right )_V $$

Physics
$$ v = f \lambda \,\!$$

$$ c = \lambda \nu \,\!$$

$$ E = h f \,\!$$

$$ E = h \nu \,\!$$

$$ t_{\frac{1}{2}} = \frac{\ln{2}}{\lambda} $$

$$ \lambda = \frac{\ln{2}}{t_{\frac{1}{2}}} $$

$$ N(t) = N_0 e^{- \lambda t} \,\!$$

$$ \frac{dN}{dt} = - \lambda t $$

$$ I(x) = I_0 e^{- \mu x} \,\!$$

$$ \lambda = \frac{h}{p} $$

$$ p = mv \,\!$$

$$ \mathbf{p} = m \mathbf{v} \,\!$$

$$ \mathbf{F} = m\frac{ d^2 \mathbf{r} }{ d t^2 } \,\!$$

$$ \mathbf{F} = \frac{ d \mathbf{p} }{ d t } \,\!$$

title: User:Ben Mills/Sandpit


text:
A-level Chemistry/OCR (Salters)/Born-Haber cycles

Atomisation
Atomisation is the process of converting an element in its standard state to a monatomic gas.

The amount of energy required to achieve atomisation is termed the enthalpy change of atomisation, ΔHat, measured in kJ mol−1.

The quantity you find in most data tables is the standard enthalpy change of atomisation, which is the amount of energy required to convert one mole of an element in its standard state to a monatomic gas, under standard conditions.

The equation for atomisation is:

 * $$\frac{1}{n} \mbox{E}_n (\sigma) \rightarrow \mbox{E(g)}$$

 * where σ represents the standard state of the element, so

 * if E is a solid is its standard state, σ = s
 * if E is a liquid is its standard state, σ = l
 * if E is a gas is its standard state, σ = g.

For example, the symbol $$\Delta H_{at}^{\circ}(\mbox{Na})$$ represents the standard enthalpy change of atomisation of sodium, $$ \mbox{Na(s)} \rightarrow \mbox{Na(g)}$$

The case of chlorine is slightly more complicated: $$\Delta H_{at}^{\circ}(\mbox{Cl})$$ represents the standard enthalpy change of atomisation of chlorine, $$ \frac{1}{2} \mbox{Cl}_2 \mbox{(g)} \rightarrow \mbox{Cl(g)}$$


text:
Wikijunior:Maze and Drawing Book

This book is supposed to be printed so that young children can color the pictures in. Please add any images to the categories below.

title: Wikijunior:Maze and Drawing Book


text:
TI-Basic 84 Programming/A Basic Program

Opening the program
To begin programming, open the Program Editor with the keystrokes PGRM:NEW. Then enter the desired name of your program and press enter. The program should be completely blank. The following examples are the only ones that will show the actual program name.

For the sake of this chapter, the program's name is TEMP.

Enter
Here's the initial screen - your clean slate.

Hitting the ENTER key will add a new line. After pressing ENTER, the screen will look like this:

Hello, World
Now, one of the most very basic programs will be created: Hello, World!

Enter the list of commands as follows:
 * PGRM:I/O:8 (ClrHome)
 * ENTER
 * PGRM:I/O:3 (Display)
 * "HELLO, WORLD!"

Make sure that "HELLO WORLD" is enclosed in quotation marks or string markers. To use them, key ALPHA +. If you followed the commands, the program should look like -

The ClrHome command clears the home screen, removing any clutter on it before your program started. The Disp command displays anything after it. There are other ways of displaying output, but Disp is the simplest. To run the program, press 2nd:Quit(Mode) then PGRM, find the program in the menu, and hit enter. The program name will be prefixed by 'pgrm' when displayed on the homescreen ("prgmTEMP"). Press enter again and the program will run, displaying:

And that's your first program. A more thorough explanation of each command used can be found in later chapters.

To edit the program again, go to PGRM:EDIT and find the name of the program.

After toying around with the program editor for a while, you might have noticed something if you've had experience programming. There's no indentation. This may be a scary notion - after all, how do you keep track of those blocks of code? The lack of indentation does interfere with readability, but there is simply not enough screen real estate to allow for indentation. The screen resolution on your calculator is extremely poor, and individual pixels can be seen with the naked eye without squinting. Unfortunately, it's one of the things you'll just have to get used to in TI-BASIC programming.

title: TI-Basic 84 Programming/A Basic Program


text:
Cookbook:Basic Cobbler

| United States | Dessert

Ingredients

 * ½ cup (1 stick) butter
 * Salt (optional; add only if butter is unsalted)
 * 1 tsp baking powder
 * 1 cup self-raising flour
 * 1 cup milk
 * 1 cup white granulated sugar
 * 1 cup fresh fruit (e.g. peaches, blackberries, cherries, etc.)

Procedure

 * 1) Preheat oven to 350°F (175°C).
 * 2) Place the butter in a deep 9½ x 12-inch baking dish. Put dish in oven to melt butter while preparing other ingredients. If butter is unsalted, add a touch of salt to the pan as well.
 * 3) Add flour and sugar to a bowl and sift together lightly. Create a well in the center of the mixture, and pour the milk into the well. Mix together with a wire whisk until smooth.
 * 4) Remove pan from oven. Pour batter into dish on top of melted butter. Do not stir. Spoon the fresh fruit out evenly across the top, but again, do not stir.
 * 5) Place cobbler in oven and bake uncovered until golden brown.

title: Cookbook:Basic Cobbler


text:
A-level Chemistry/OCR (Salters)/Buffer solutions

Calculating the pH of a buffer solution
$$\mbox{pH} = -\log_{10}{ \left ( K_a \frac{\left [ \mbox{acid} \right ]}{\left [ \mbox{salt} \right ]} \right ) }$$

Derivation
For any equilibrium

$$ a\mbox{A} + b\mbox{B} \rightleftharpoons c\mbox{C} + d\mbox{D} \,\!$$

the equilibrium constant, K, is defined as

$$ K = \frac{ [\mbox{C}]^c [\mbox{D}]^d }{ [\mbox{A}]^a [\mbox{B}]^b } $$

Therefore, for the dissociation equilibrium of any acid

$$ \mbox{HA} \mbox{(aq)} \rightleftharpoons \mbox{H}^+ \mbox{(aq)} + \mbox{A}^- \mbox{(aq)} \,\!$$

the acid dissociation constant, Ka, is defined as

$$ K_a = \frac{ [\mbox{H}^+ \mbox{(aq)}] [\mbox{A}^- \mbox{(aq)}] }{ [\mbox{HA} \mbox{(aq)}] } $$

This equation can be rearranged to make [H+(aq)] the subject:

$$ [\mbox{H}^+ \mbox{(aq)}] = K_a \frac{ [\mbox{HA} \mbox{(aq)}] }{ [\mbox{A}^- \mbox{(aq)}] } $$

Two assumptions are required:

1 Every A− ion comes from the salt

 * Although this is not quite true, it is a close enough that the pH value we get from the final equation is very close to that found experimentally. It allows us to assume that

 * $$ \left [ \mbox{HA} \mbox{(aq)} \right ] = \left [ \mbox{acid} \right ] $$

2 Every HA molecule remains undissociated

 * Again, despite being slightly inaccurate, this assumption creates the following useful equation

 * $$ \left [ \mbox{A}^- \mbox{(aq)} \right ] = \left [ \mbox{salt} \right ] $$

The equations in assumptions 1 and 2 allow us to replace [A−(aq)] with [salt] and [HA(aq)] with [acid] as follows.

The effect of assumption 1 is that

$$ [\mbox{H}^+ \mbox{(aq)}] = K_a \frac{ [\mbox{HA} \mbox{(aq)}] }{ [\mbox{A}^- \mbox{(aq)}] } $$

becomes

$$ [\mbox{H}^+ \mbox{(aq)}] = K_a \frac{  [\mbox{HA} \mbox{(aq)}] }{ [ \mbox{salt} ] } $$

The effect of assumption 2 is that

$$ [\mbox{H}^+ \mbox{(aq)}] = K_a \frac{ [\mbox{HA} \mbox{(aq)}] }{ [ \mbox{salt} ] } $$

becomes

$$ [\mbox{H}^+ \mbox{(aq)}] = K_a \frac{ [\mbox{acid}] }{ [ \mbox{salt} ] } $$

By definition,

$$\mbox{pH} = -\log_{10}{ \left ( \left [ \mbox{H}^+ \mbox{(aq)} \right ] \right ) }$$

so

$$\mbox{pH} = -\log_{10}{ \left ( K_a \frac{\left [ \mbox{acid} \right ]}{\left [ \mbox{salt} \right ]} \right ) }$$