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Physics with Calculus/Mechanics/Motion in One Dimension

Motion in One Dimension
As physics, at its essence, is the study of motion, we will begin our book with the study of motion, in one dimension.

To simplify our discussion, we will want to create a model of the real objects we will be discussing. Thus, we create the concept of a "particle". A particle, simply, is a very small object, one whose length, width, and height are negligible. With this concept of a particle, we can unambiguously define the distance from it to the origin, without having to worry about from what point we measure the object.

Position
Consider a particle restricted to movement along a single line. Its position can be described with a single number, x. This number can be thought of as the particle's distance from the origin, or the magnitude of the vector pointing from the origin to the particle. The actual displacement of the particle is actually a vector with one entry (because we are working in one dimensional space), but because the direction is known it can be specified unambiguously by the magnitude alone.

The value x is measured in meters, and in order to interpret it, a particle and a reference frame, or coordinate system, must be implied. If the particle does not remain in the same place at different times, then the value of x will change in time, and thus we can define a function x(t) which returns the position of the particle at a point in time t. For example, say we have a particle with position function x(t)= 2t. Its position at t = 3 is x(3) = 2(3) = 6 m along the x-axis. For a particle with position function x(t)= t2 + 5, its position at t = 7 s is x(7) = 72 + 5 = 54 m along the x-axis.

Velocity
Consider the graph of a position function. Under any known physical conditions, this function must be continuous — if it were discontinuous, that would allow the possibility that objects could spontaneously jump from place to place. Furthermore, as we shall see at the end of this section, the position function is also twice differentiable. Under these conditions, we are able to see that the function has a well defined rate of change everywhere.

Velocity, in one dimension, is the measure of the rate of change position per unit time, and is measured in meters per second. The simplest way to measure velocity is to measure the time position of a particle at two different times, and divide the change in position (displacement) by the change in time. As a formula:

$$\bar{v} = \frac{\Delta x}{\Delta t} = \frac{x_f-x_i}{t_f-t_i}$$ where xf and xi are the final and initial distances respectively and tf and ti are the final and initial times.

Notice that since the numerator has units of length and the denominator has units of time, the quotient has units of length divided by time. In SI, the units of velocity are the derived units of meters per second. Common non-SI units of velocity include miles per hour and knots. Example 1: A particle starting at the origin has moved 27 m in 9 s. Find $$\bar{v}$$.

$$\bar{v} = \frac{x_f-x_i}{t_f-t_i}

= \frac{27\ \mathrm{m} - 0\ \mathrm{m}}{9\ \mathrm{s}-0\ \mathrm{s}}

= 3\ \mathrm{m}/\mathrm{s}$$

Example 2: A particle starting 23 m from the origin has moved to 43 m in 5 s. Find $$\bar{v}$$.

$$\bar {v} = \frac{x_f-x_i}{t_f-t_i}

= \frac{43\ \mathrm{m}-23\ \mathrm{m}}{5\ \mathrm{s} - 0\ \mathrm{s}}

= \frac{20\ \mathrm{m}}{5\ \mathrm{s}}

= 4\ \mathrm{m}/\mathrm{s} $$

There is a limit, however, to what average velocity can tell us. For example, it's entirely possible that the speed of a particle varies with respect to t, and we want to determine the velocity of the particle at a certain instant in time. To do this, we take the average velocity over a smaller and smaller time interval, that is,

$$\ v(t) = \lim_{\Delta t \to 0} \frac{\Delta x}{\Delta t}$$

Expanding this, we get

$$ v(t) = \lim_{\Delta t \to 0}\frac{x(t_f) - x(t_i)}{t_f - t_i}$$

And rewriting $$t_i$$ and $$t_f$$ as t and t+$$\Delta t$$, we get

$$ v(t) = \lim_{\Delta t \to 0} \frac{x(t + \Delta t) - x(t)}{\Delta t}$$

Which is the definition of the derivative. Therefore,

$$\ v(t) = \frac{dx}{dt}$$

Example 1: A particle's motion is described by the equation $$\ x(t) = 3t^2 + 5t + 2$$. Find a) the particle's velocity function, and b) its instantaneous velocity at t = 4 s.

a) $$

v(t) = \frac{dx}{dt}

= \frac{d}{dt} (3t^2 + 5t + 2)

= 6t + 5$$

b) $$

\ v(4) = 6(4\ \mathrm{s}) + 5

= 29\ \mathrm{m}/\mathrm{s} $$

Acceleration
Just as the time derivative of a particle's position function has a significant meaning, that is, its velocity, so too does the time derivative of the velocity function. In this case, it is known as the acceleration of the particle. You may have heard of acceleration previously, such as when referring to cars or other vehicles. Acceleration is measured in meters per second per second, or m/s2, read 'meters per second squared.' Some old texts use the equivalent phrase 'meters per second per second.'

Average acceleration, or $$\bar{a}_x$$ is similar to average velocity in that it is independent of the path taken by the particle; it is simply the change in velocity divided by the change in time: $$ \bar{a} = \frac{v_{xf} - v_{xi}}{t_f - t_i} = \frac{\Delta v_x}{\Delta t} $$

And again, through a similar derivation, we arrive at the definition of instantaneous acceleration:

$$a(t) = \lim_{t \to 0} \frac{\Delta v}{\Delta t} = \frac{dv}{dt}$$

Since the velocity is a derivative of the original position function, we can also say that the instantaneous acceleration is the second derivative of the position function, which would be written as follows:

$$a(t) = \frac{d^2x}{dt^2}$$

Exercises
 Given a particle moving in one dimension with position function x(t) = 5t3 – 8t2 + 20: Determine the velocity v as a function of time t. Determine the acceleration a as a function of time t. At what time(s) will the particle come to a momentary stop? At what time(s) will the particle's acceleration be zero?  A particle in simple harmonic motion has a position defined by the function x(t) = (80 cm) sin [(20 s-1)t]. Determine the velocity v as a function of time t.

Determine the acceleration a as a function of time t.

What is the period of the particle's motion? (That is, how long does it take for the particle to return to the position and velocity at which it started?)

Excluding the effects of air resistance, an apple falls from a tree with a constant acceleration of 9.8 m/s2.

What is the apple's velocity v(t)?

What is the apple's velocity after one second of freefall?

What is the position x(t)?

What is the position after one second of freefall? Two seconds? Three seconds?

Motion in Two or Three Dimensions
Describing the motion of a particle in two or more dimensions can be more complex than in one dimension, because, instead of having only two directions in which to move (back and forth along the x-axis) there are an infinite number of paths a particle can take. In order to properly describe the motion of a particle, we must use vectors.

Position
When dealing with motion in one dimension, we could describe an object's position with a single variable, its location along the x-axis. Now that we have two or more axes, we need one variable per axis to describe a particle's location. We can use a position vector, denoted r, to describe the location of this particle. In the two-dimensional case, the position vector is drawn from the origin to the location of the particle in the Cartesian plane and has two coordinates, the x-position of the particle, and the y-position of the particle.

Example 1: The position of a particle at (4, 5) on a Cartesian plane can be described as 4 units along the x-axis, and 5 units along the y-axis, or as the position vector r = <4, 5> = 4i + 5j, where i and j are the unit vectors in the x and y direction, respectively.

From this example, we can see that a position vector takes the form <x, y>, where x is the distance moved along the x-axis and y is the distance moved along the y-axis.

Example 2: A carbon atom sits 7.0 nm east, 0.5 nm north, and 3.0 nm below the tip of a scanning tunneling microscope. Its position vector r = <7.0 nm, 0.5 nm, –3.0 nm>. Taking i to be east, j to be north, and k to be up, r = (7.0 nm)i + (0.5 nm)j + (–3.0 nm)k.

Displacement
Recall that the displacement of a particle is the difference between its initial and final positions. In two dimensional motion, we denote the displacement vector as Δr. The displacement vector is defined as:

$$ \Delta \mathbf{r} = \mathbf{r}_f - \mathbf{r}_i $$

The direction of the displacement vector is the straight line between the starting point and the termination point of a particle's path.

Velocity
As with motion in one dimension, we still retain the concepts of average and instantaneous velocity; the only difference is that we now must treat the change in position as a change in the position vector. Thus, the average velocity in two dimensions is

$$ \bar{\mathbf{v}} = \frac{\Delta \mathbf{r}}{\Delta t} $$

Since, like displacement, $$ \bar{\mathbf{v}} $$ is independent of path, the direction of $$ \bar{\mathbf{v}} $$ is along $$ \mathbf{r}$$.

Like its one-dimensional analog, the instantaneous velocity v is calculated by finding the time derivative of the vector displacement r:

$$ \mathbf{v} = \frac{d\mathbf{r}}{dt} $$ COUT <<SAFA;

Acceleration
Just as with the one-dimensional case, the average and instantaneous accelerations can be calculated using derivatives and limits.

The average acceleration is given by: $$\bar{\mathbf{a}} = \frac{\mathbf{v}_f - \mathbf{v}_i}{t_f - t_i} = \frac{\Delta \mathbf{v}}{\Delta t}$$

The instantaneous acceleration is given by: $$\mathbf{a} = \frac{d\mathbf{v}}{dt} = \frac{d^2\mathbf{r}}{dt^2}$$.


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Talk:Cocoa Programming

Initial Comments
As Cocoa is not only the name for a set of frameworks/APIs (primarily Foundation and AppKit but including many more) but also the name for an application environment within Mac OS X this topic will need a clear introduction and careful use of terminology.

I will wait for interested parties to discuss the direction of this book before making wholesale changes but I propose that this book head in the following direction:

Overview

 * The Cocoa Application environment
 * Cocoa Applications
 * Cocoa Frameworks
 * Foundation Framework
 * Application Kit Framework
 * Possible Languages
 * Objective-C
 * Java
 * AppleScript
 * Others (Python, Ruby, Shell Scripting, Tcl, etc)

Beginning Cocoa Programming
Creating an example (AppleScript?) program from installation through to compilation to show readers the basic tasks involved in writing an application.
 * Developer Tools
 * Installing Developer Tools
 * The Development Environment
 * Starting the Project
 * Building the Interface
 * Writing the Code
 * Running the Application

Cocoa Principles
Start building an example Objective-C program (refer readers to Programming:Objective-C if necessary?) to teach Cocoa programming principles and basic features.
 * Objects
 * Root class (NSObject)
 * Basic Cocoa objects
 * MVC
 * Model
 * View
 * Controller
 * Object Modelling
 * Entities
 * Properties
 * Creating a Graphical User Interface
 * Windows
 * Views
 * Controls
 * Menus
 * Text Views
 * Connections

Common Cocoa Features
Add some additional features to the program that introduce intermediate features.

Completing a Cocoa Application
Complete the program and incorporate advanced Cocoa features.

Other Comments
As this is a Programming Cocoa book (not a programming OpenStep or GNUstep book) I think that in general it should focus on Cocoa. A chapter or part devoted to how the book relates to GNUstep would be helpful for those who are interested but I think trying to make the entire book relevant to both Cocoa and GNUstep programmers is going to add unneccessary complexity and end up confusing both.

Additional topics obviously need to be added to Parts 3 & 4. Splitting features into "basic", "intermediate" and "advanced" can be somewhat arbitrary but should help divide the book into more manageable chunks.

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

title: Talk:Cocoa Programming


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Cookbook:Pupusas

| Cuisines

A pupusa is a stuffed corn-tortilla, usually served with a spicy coleslaw called curtido. Pupusas originated in El Salvador, but immigrants have taken the dish to other Central American countries and beyond. Pupusas are hand-made and thick. Like all corn tortillas, they are made using corn masa. They are stuffed with one or more of the following: There are also the pupusa revueltas (with mixed ingredients of cheese, pork, and beans). Pupusas are usually served with curtido and tomato sauce. They are eaten with the fingers.
 * cheese (queso) (usually a soft Salvadoran cheese called Quesillo)
 * fried pork rind (chicharrones)
 * chicken (pollo)
 * refried beans (frijoles refritos)
 * queso y Loroco (loroco is a shrub flower bud from Central America)

Dough

 * Corn masa
 * Water

Cheese filling

 * 3 cups of shredded cheese (use a combination of hard and soft cheese; you can mix frying cheese, mozzarella, and ricotta)
 * 3–4 tablespoons of heavy cream
 * ½–1 cup of loroco (this can be hard to source, so you can use very finely chopped green peppers or scallions instead)
 * Salt to taste

Chicharron (pork rind filling)

 * 1 cup bacon
 * Garlic (optional), minced
 * 4–5 tomatoes
 * 1 green pepper
 * Salt to taste

Revueltas filling

 * Ground and fried beans (can be canned or prepared from your favorite recipe)

Dough

 * 1) Follow the instructions on the bag of masa for making tortilla dough, and make as much dough as needed. One pupusa uses about as much dough as two tortillas.
 * 2) Set the dough aside while you prepare the filling.

Cheese filling

 * 1) Make a paste with all of the ingredients. To avoid the paste leaking out of the pupusas, it should not be too soft.

Chicharron filling

 * 1) Cook the bacon with some garlic. Set fat aside but do not discard.
 * 2) Once cooked, grind bacon with the tomatoes, green pepper, and salt to taste.
 * 3) Mix in some of the bacon fat until it has a soft consistency.

Revueltas filling

 * 1) Prepare the ground and fried beans as desired.

Assembly

 * 1) Shape and fill 2 tbsp of the dough per pupusa using one of the two methods below. When filling the pupusas add some of the bean, chicharrón, and/or cheese fillings.
 * 2) * Beginner method: Shape the dough into a ball, and clap it between your hands until you make a round, thin tortilla about ⅛ in thick. Continue making more tortillas this way. Put some filling on one tortilla, cover with another, and press the sides to seal them.
 * 3) * Experienced method: Shape the dough into a ball, then insert your thumb in the ball to make a hole in the center. Fill the hole with some filling, and seal the hole by pushing and pinching the dough on the sides up. Carefully clap the pupusa between your hands to flatten it without pressing out the filling.
 * 4) Cook the pupusas on a lightly greased griddle, pan, or electric pancake griddler over low-medium heat (325–350°F) on one side, then the other until they are cooked. Each side will be ready when it no longer sticks to the pan (depending on the thickness of the tortillas, this might take 4 minutes or more per side).
 * 5) Top the pupusas with curtido and tomato sauce.

Notes, tips, and variations

 * There are different brands of corn masa to make the dough. MASECA, which can be found in most large American supermarkets in the international section, is one of them but there are others.
 * If you can find it, try replacing the cheese filling with prepared queso con loroco. You won't get the authentic flavor from a pupusa if you use American ingredients.

title: Cookbook:Pupusas


text:
User:Ross Uber/sig

Ross Uber -  Talk  -  Contributions  -

title: User:Ross Uber/sig


text:
Cookbook:Refried Beans

| Southwestern U.S. cuisine | Tex-Mex cuisine

Oddly enough, refried beans (frijoles refritos) are only fried once. The prefix "re" is a Spanish prefix meaning "very" or "well", inappropriately tacked onto a non-Spanish word.

Ingredients

 * Pinto beans or black beans
 * Butter (optional) or home-rendered lard (optional)

Procedure

 * 1) If using dried beans, wash them then cover with water in a medium pot and simmer according to the package directions. You may add onion halves or a ham bone, which you can remove at the end.[[Image:BeansHamPot.jpg|thumb|339x339px|Cooked [[Cookbook:Bean|Beans]] and ham bone]]
 * 2) If using canned beans, rinse them briefly before use.
 * 3) Smash the beans, perhaps with a potato masher.
 * 4) Add home-rendered lard or butter, totaling up to 20% of the total (25% of the amount prior to adding). You may also use a substantially smaller amount of some other oil or omit it entirely.
 * 5) Fry the beans, stirring and turning them until they thicken to the degree you desire, which can be anywhere from soupy to parched.

Use

 * Burrito
 * Pupusa

Livre de cuisine/Frijoles refritos

title: Cookbook:Refried Beans


text:
Talk:Bicycles/Maintenance and Repair/Tools and Supplies/Truing Jig

It is possible to make your own truing jib. Start by getting an old bicycle fork and finding a way of supporting it. The easiest way is to find a sturdy box, and drilling a hole big enough to accommodate the fork neck. The hole should be tight enough to firmly hold the fork and the wheel which will be supported. The fork is now upside down. It is possible to fashion some kind of true indicator or caliper using a nail or pencil attached on one leg of the fork. A metal strap that can be attached with a screw as a pencil or nail holder works best. I try to avoid using tape, string or rubber band since they have a tendency to move which could affect an accurate reading of the wheel's straightness. Straight wheels tend to turn smoothly without deviation when viewed from the front. I start by bringing the nail as closely as possible to the wheel rim. Turning the wheel by hand, warped wheels will occasionally touch the rim or show a large gap. Wheel spokes work by providing enough pull or release on both sides of the rim so that the rim remains straight. By loosening one spoke, the tension is strengthened on the other side and vice-versa. Ideally the spokes on both sides should be even to maintain optimum rim straightness. A sequence of tightening and loosening both sides of the spokes where necessary is the key to rim straightness.


text:
Template:Copyvio

This adds a page to Category:Copyright violations and after 7 days to Category:Candidates for speedy deletion.

title: Template:Copyvio


text:
Gujarati/Vocabulary

નમસકાર Namaskaar or નમસતે Namaste
 * Hello

કેમ છો ? Kem chho?
 * How are you?

મારું નામ હરશલ છે. Maarũ naam Harshal chhe.
 * My name is Harshal.

આવજો ! Aavjo!
 * See you later/goodbye

તમારું નામ શું છે ? Tamaarũ naam shũ chhe?
 * What is your name?

તમે ક્યાં રહો છો ? Tame kyãã raho chho?
 * Where do you live?

તમે ઘરે ક્યારે આવશો ? Tame ghare kyaare aavsho?
 * When will you come home?

તમે શું કરો છો ? Tame shũ karo chho?
 * What are you doing?

How are your exams going?

title: Gujarati/Vocabulary


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Cookbook:Peeler

| Kitchen tools

A peeler (sometimes potato peeler or vegetable peeler) is a kitchen utensil used to remove vegetable peels, particularly from potatoes. Often it will have a semi-sharp point that can be used to gouge out bad spots.

title: Cookbook:Peeler


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Talk:Japanese/Vocabulary/Linguistics

Untitled
Does anybody remember what the Japanese word for counters is? That might be a useful one to add.

I think there are certain terms here that need to be in different sections. I guess as the list grows, it will probably separate into phonetics/phonology, morphology, syntax etc.

title: Talk:Japanese/Vocabulary/Linguistics


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User talk:User142~enwikibooks

Type Affinity vs. Type Matching
The usage of these two terms is inconsitent in Pokémon. Whereas your main contributions use "type matching", the remainder use "type affinity". A general consensus on the proper term should be reached. KelvSYC 04:49, 18 May 2005 (UTC)

Contributor's Guide
Thought I'd let you know that as a big contributor to Pokémon, you might like to put your name up at Pokémon:Contributor's Guide. That way, people will know that you are a big contributor. KelvSYC 05:41, 23 May 2005 (UTC)

Dittoboy
Do you go to Bar-Ilan university? If so, maybe you could talk to the staff there about this guy. I know that (s)he used the IP address "132.70.50.117" on 8 May 2005 at 06:53 UTC. The same IP was also used on 26 May 2005 at 17:06 and 17:29, unless it's somebody acting like the same person.

That information should be enough to find out who he is, that is of course, if they keep logs.

Warm regards,

Frazzydee|✍ 21:50, 30 May 2005 (UTC)

 * By the way, does blocking that one IP actually cause the entire university to be blocked? RIPE seems to show that Bar-Ilan owns from 132.70.0.0 - 132.70.255.255 (I think...). -Frazzydee|✍ 23:57, 30 May 2005 (UTC)

 * Yes. I've tried on several computers (some are Windows, others are Linux etc.), and they all say the same thing. Yes, I know that the entire 132.70.*.* block is used by the university, and that they also own 132.71.*.* (this block is one they didn't need to start using). In addition, I know that 132.70.1.6 is a particular Solaris Unix computer (its name is Sunshine), and when I log on to that computer and try to edit I get the same message.

 * For your information, the exact name of the computer "132.70.50.117" is "proxy1.cc.biu.ac.il".

 * By the way, about "if they keep logs", some of the computers are ones which no one needs to log on to - and if no one sees who's working there and nothing personal is loaded, no one knows who it is. This includes library catalog computers in the libraries here (many departments have their own), all of which are connected to the internet; 4 computers in the student union building for use of the students; a computer room intended for students to use. (I'm a student in the computer department, so I usually use the computers for the students of the department.)

 * User142 11:05, 31 May 2005 (UTC)

More dittoboy troubles
Hi there,

Hopefully you remember me, it's been a while...how are you?

At Wikipedia, there are still issues with whoever is trying to get Bar-Ilan blocked. Do you still go there? Recently, an IP used by the university (may be the entire university's proxy IP, not sure) was blocked indefinitely. Could you do me a favour and find out what can be done? Maybe if they took a few minutes to look over their logs they can find out who it is and restrict their access.

Anyhow, this has gone on for way too long, so I don't disagree with a more long-term block at this point in an attempt to get your University's attention. Hopefully this can get resolved as soon as possible. If you can get someone at your university to listen, they can email me at wiki [a t] frazzydee [d O T] ca, or they can email the blocking admin here.

Sorry about this- I want a long-term block as little as you do, but it's a little hard for me to argue against it when it's gone on so long and nobody from Bar-Ilan has responded to me.

Kind regards, Faraaz/Frazzydee|✍ 04:21, 31 March 2006 (UTC)

old templates...
Hi User142,

Are you still around? I was going through the templates and there was one (Template:PoisonType) that I'm not sure what it was used for (it doesn't link anywhere, but that doesn't mean it wasn't used with subst).

OK to delete it? -- SB_Johnny | talk 15:36, 17 August 2006 (UTC)

Your account will be renamed
Hello,

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.

Unfortunately, your account clashes with another account also called User142. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name User142~enwikibooks that only you will have. If you like it, you don't have to do anything. If you do not like it, you can pick out a different name.

Your account will still work as before, and you will be credited for all your edits made so far, but you will have to use the new account name when you log in.

Sorry for the inconvenience.

Yours, Keegan Peterzell Community Liaison, Wikimedia Foundation 23:51, 17 March 2015 (UTC)

Renamed
 This account has been renamed as part of single-user login finalisation. If you own this account you can |log in using your previous username and password for more information. If you do not like this account's new name, you can choose your own using this form after logging in: . -- Keegan (WMF) (talk) 05:37, 19 April 2015 (UTC)

title: User talk:User142~enwikibooks


text:
Organic Chemistry/Dienes/Kinds of dienes

Organic chemistry > Dienes > Kinds of dienes

<< Dienes | Conjugation >>

Dienes have two or more carbon-carbon double bonds which may be either isolated (R'-C=C-R-C=C-R'), cumulated (R-C=C=C-R), or conjugated (R-C=C-C=C-R). Each state represents a different stability due to electron delocalization, and the conjugated form is generally favored in organic molecules.

Isolated Dienes
Isolated dienes typically show no "special" stability. Their two π-bonds interact independent of one another and they compete as intermolecular reaction sites depending on steric, kinetic, and thermodynamic factors. Often, these types of dienes can be treated merely as larger, more complex alkenes, because the two bonds are said to have "communication" (proximal electron delocalization due to location).

Isolated dienes are not considered to be especially useful in common synthesis reactions, although intermediates may often take the form of an isolated diene.bb

Cumulated Dienes
Cumulated dienes are typically less stable than other alkenes. The main reason for the instability is the fact that this sort of diene is a probable transition state for an alkyne's triple bond to move down the carbon chain towards the most stable position. As you may recall, rotation does not occur around any π-bond, which means that cumulated double bonds can lead to a less stable, higher energy compound being formed.

Typically, cumulated dienes are discussed only in advanced courses in organic chemistry, and so they will not be discussed in detail here. Beginning organic chemistry students should merely remember that cumulated dienes are 1) high energy and 2) most likely found as transition states.

Conjugated Dienes
Conjugated dienes are dienes which have at least two double bonds separated by a single carbon-carbon bond, and for this reason conjugated dienes are observed to have a special stability due to the overlap of electron orbitals. The areas of concentration of negative charge (electron density) overlap across the three bonds (two double bonds and one single bond) forming what behaves essentially as a single, continuous π-bond across three carbon atoms. This delocalization of electron density stabilizes the molecule, resulting in the arrangement of lowest energy.

Atoms other than carbon which are capable of multiple bonds may also participate in conjugation. The heteroatoms most often associated with conjugation in dienes and other molecules are nitrogen and oxygen, but theoretically the majority of atoms in the Periodic Table of Elements could participate in conjugation chemistry. Most often, in organic molecules, heteroatoms participating in conjugation will be nitrogen atoms within a ring structure or a double-bonded oxygen attached to form a ketone or aldehyde.

Conjugation of double bonds is the largest part of what makes aromaticity relevant in organic chemistry, and conjugated double bonds have many other significant impacts on other types of dienes as well.

<< Dienes | Conjugation >>


text:
Talk:Esperanto/Traveling

Ĉu
'Ĉu' is not only for questions of yes and no. Also it is used for questions with two or more alternatives.

"Ĉu vi volas teon aŭ kafon?

Keep it up!
I just wanted to say to whoever has been writing this book that as a learner Esperantist (if that is a word!) I've found it useful, and it would be great to see more modules added!

Tio?
In this lesson, it defines tio as "that." Though really isn't it more like "this"? 68.55.18.191 20:28, 10 December 2005 (UTC)

some suggestions
For the Ludoviko baggage scenario, please would you consider the following suggestions to aid clarity: 1. The sentence, "Ludoviko revenis lian edzinon." means that Ludiviko returned to someone else's wife! The "lian" needs to be replaced with the reflexive "sian" to show that he returned to his own wife! 2. The sentence, "Jes, ĝi trovita de virino bona estas." seems a wee bit awkward. An alternative could be, "Jes, ĝi estis (or estas) trovita de virino bona." so keeping the verbal bits together! Or, better still, avoiding the passive voice altogether and going for: "Jes, bona virino trovis ĝin." Thank you for considering this. Stelalumo (discuss • contribs) 09:29, 27 July 2017 (UTC)

title: Talk:Esperanto/Traveling


text:
File:Rotation of a rectangle.png

Demonstrates the rotation (mechanical) of a rectangle.

title: File:Rotation of a rectangle.png


text:
Movie Making Manual/Film stock

Since the rise of digital cameras, film is not always needed. =Types of Film stock=

8mm
Amateur film gauge introduced by Eastman Kodak. In the camera, it was the same size with standard 16mm film but with double perforations. At the picture area of a typical 16mm film, four frames of 8mm were recorded, two in the first run and two when turning the film cassette to the other side to expose the other half width, much like audio cassettes are used. When processed, it was slit lengthwise to produce a double length (usually 50ft) Regular 8mm film for projection. A better variant, Super 8mm was introduced by Eastman Kodak in 1965. This had smaller perforations which allowed for 50% increase of the image size and hence more detail could be recorded. The larger frame also allowed for larger projection sizes than were possible with standard 8mm (called Regular 8mm) film. See also respective sections in Wikipedia and Kodak's web site.

Super 16mm
Super 16mm film is physically 16mm wide, however, when compared to standard 16mm film one will notice that 16mm has perforations on both edges of the film, whereas super 16mm only has perforations on one side. This allows for a wider frame on the film and provides greater resolution to that achievable with standard 16mm film stock.

35mm
35mm Film Stock is regarded as the industry standard when it comes to professional productions. There are a few different types of 35mm film, including:

 * Two perf
 * Three perf
 * Four perf
 * Super 35mm

65/70mm
This type of film stock is the largest format made, it is generally used for IMAX productions. It is the highest quality film available.

Kodak
You can purchase Filmstock directly from Kodak by calling them. Information is at http://www.kodak.com

Fuji

 * Consider using cheaper Short end and Re-can stocks.

Storing Filmstock

 * Shameless Plug for Kodak... http://www.kodak.com/global/en/service/tib/tib5202.shtml

/Tools and equipment /Pre-production /Production /Cinematography

title: Movie Making Manual/Film stock


text:
Reaktor/Modules/Subtract

You can subtract signals or numbers in Reaktor with this module. subtraction: $$36-11=25$$

36 is subtracted by 11 to get 25.

How to use column subtraction?

Example:

 * 36－11＝25

$$\begin{align} { 36 }\\ \underline{ -11}\\ { 25 } \end{align}$$

 * 36－5－11＝20,36－11－5＝20

 * $$\begin{align}

{36}\\ { 5}\\ \underline{-11}\\ {20} \end{align}$$

 * $$\begin{align}

{36}\\ {11}\\ \underline{- 5}\\ {20} \end{align}$$

title: Reaktor/Modules/Subtract


text:
User talk:Alcinoe~enwikibooks

I added Public Domain Tags to the photos - I like to make all my work public domain - I just forgot to add the tags when I downloaded them.

About the French Fry picture - My mother made the fries in the picture, and did not use a recipe - I read the fry recipe and I think that they would look exactly the same as the ones in the picture.

Image
I think you cooked the Cookbook:French Fries recipe. If so, you might want to make a note of that on the FrenchFries1.jpg page and on the image caption. Some people have used generic pictures in the past, not exactly matching up with the recipe.

BTW, nice cookie pictures. (same thing about ChewyGingerCookies.jpg and CrispyGingerbreadCookies.jpg too of course — a note on the image page would be informative)

Never mind my earlier comment (see history if you care) about copyright tags; that isn't required for wikibooks. I'm more used to uploading at the Commons, where the image would soon get deleted if it was without copyright tags.

AlbertCahalan 17:46, 18 May 2005 (UTC)

So... how were the cookies? Which recipe makes better cookies? Since these recipes are now among the dozen or so with pictures (thank you), they are likely to end up as featured recipes. Probably the recipe talk pages are a good place to note how things turned out. AlbertCahalan 22:07, 18 May 2005 (UTC)

Copyright problem with Image:FreshMozzarellaBruschetta.jpg
--Derbeth 07:42, 4 October 2005 (UTC)

Image:BreadKnife.jpg
Please check all you files. This one has no license. --Derbeth talk 08:48, 18 January 2006 (UTC)

Pictures
As you can see at the top of this page, "All unlicensed images uploaded to wikibooks before November 1, 2006 will soon be deleted." You have uploaded images and some of them are untagged. You can see them here. Please review them and add appropriate tags. If you have any questions, feel free to ask me. --Think Fast 04:29, 13 November 2006 (UTC)

(A bit late but ...) Welcome message
Hello, and welcome to Wikibooks!

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Good luck! --Panic 00:45, 4 October 2007 (UTC)

Cookbook:Grammy's Potato Salad
Hi! Your recipe for Grammy's Potato Salad has been tagged as needing work for about 5 years now, and all that's missing is a quantity. You list:

 * 1/4 sweet pickle juice (from jar of pickles)

but you fail to specify 1/4 what. (Cup?)

Can you edit your recipe to correct this, please? Thanks!—D'Ranged 1 talk 10:29, 29 August 2012 (UTC)

Your account will be renamed
Hello,

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.

Unfortunately, your account clashes with another account also called Alcinoe. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Alcinoe~enwikibooks that only you will have. If you like it, you don't have to do anything. If you do not like it, you can pick out a different name.

Your account will still work as before, and you will be credited for all your edits made so far, but you will have to use the new account name when you log in.

Sorry for the inconvenience.

Yours, Keegan Peterzell Community Liaison, Wikimedia Foundation 22:55, 17 March 2015 (UTC)

Renamed
 This account has been renamed as part of single-user login finalisation. If you own this account you can |log in using your previous username and password for more information. If you do not like this account's new name, you can choose your own using this form after logging in: . -- Keegan (WMF) (talk) 04:30, 19 April 2015 (UTC)

title: User talk:Alcinoe~enwikibooks


text:
User talk:Perl~enwikibooks/Fahrenheit 451

Looks great, good job. I was just thinking that on nice addition would be a section on symbols/symbolism in this book.

Needs symbolism for your books.


text:
Spanish/Present Subjunctive

../Verbs/ | ../Verb Tenses/

Gramatically, the subjunctive is called a "mood". This is differentiated from a "tense" in that it does not express time per se (which is what "tense" really means). Along with the name of the mood also goes a tense. For the subjunctive mood, the tense may be present, imperfect, present perfect, or past perfect (or pluperfect). This article only discusses the present tense.

The present tense of the subjunctive mood, as with the other subjunctive tenses, is used for a variety of situations. This variety can make the subjunctive difficult to understand for English-speakers, and make students of Spanish dread the mood.

One common situation is to indicate actions which the speaker wishes will happen or wants to happen. It follows phrases such as "Espero que" (I hope that) and "Quiero que" (I want), and always "Ojalá que" (God willing/Hopefully). Similarly, another situation is where the speaker fears or doubts the action will happen. Phrases such as "Temo que" (I fear that), "No creo que" (I don't think that), "Dudo que" (I doubt that). Yet another situation is where the speaker is expressing possibilities or expressing beliefs that are impersonal yet still subjective. Examples here are "Es posible que" (It's possible that), "Es mejor que" (It's best that), "Podría ser que" (It could be that).

Note that the common thread in all these cases is that the action in the subordinate clause is not a factual statement, but something only from the realm of possibility. In some cases you are hoping it is true, in others you are doubting, denying, or speculating about its reality; but in all cases, you are essentially mooting the statement, bringing its reality up for discussion. This mooting is the essence of the subjunctive. You put the action that you are mooting in a subordinate clause, almost always joined to the main clause by "que." (In fact, this is where the name "subjunctive" came from: you are joining another idea or clause in a subordinate relationship to the main clause.)

There are some other uses of the subjunctive.

In order for the subjunctive to be used, you must have both:
 * Expression of desire, doubt, hope, fear, or one of the other situations above, and
 * Change of subject between independent clause and dependent clause (Yo quiero que Ud. me ayude-- I want you to help me.)

Conjugations
Rule: The subjunctive begins with the yo-form of the present indicative. Then remove the -o and append the "opposite" endings.

Hablar hablo -> habl-

 * Yo hable
 * Tú hables
 * Él/Ella/Ud. hable
 * Nosotros hablemos
 * Vosotros habléis
 * Ellos/Uds. hablen

Comer como -> com-

 * Yo coma
 * Tú comas
 * Él/Ella/Ud. coma
 * Nosotros comamos
 * Vosotros comáis
 * Ellos/Uds. coman

Vivir vivo -> viv-

 * Yo viva
 * Tú vivas
 * Él/Ella/Ud. viva
 * Nosotros vivamos
 * Vosotros viváis
 * Ellos/Uds. vivan

It is important to note that the present subjunctive is taken from the first-person singular rather than other stems because of the many verbs that are irregular in the first-person singular.

 * Yo tengo -> tenga
 * Yo pongo -> ponga
 * Yo caigo -> caiga
 * Yo conozco -> conozca
 * Yo permanezco -> permanezca

Seeming Exceptions

1. Even though the present subjunctive takes its form from the first-person singular, you still need to watch out for vowel changes due to stress shifting in the stem. Thus,

 * Yo pueda
 * Tú puedas
 * Él/Ella/Ud. pueda
 * Nosotros podamos (not puedamos)
 * Vosotros podáis (not puedáis)
 * Ellos/Uds. puedan

2. Since Spanish always tries to keep the spelling accurate to the pronunciation, in some cases the ending needs to change because the stem ends in a 'c', 'z', 'g', etc. This change normally happens in the first-person singular of -er and -ir verbs also, but it is still something to be aware of because in speaking or writing you're not always explicitly conscious of grammatical forms other than what you're using.

 * Yo juego -> juegue
 * Yo toco -> toque
 * Yo recojo -> recoja

title: Spanish/Present Subjunctive


text:
Talk:Emergency Medicine/Stencil Chapter

This is a Template page so specific information should not go here.

Thanks KW

title: Talk:Emergency Medicine/Stencil Chapter


text:
Cookbook talk:Pie Crust

I'm not sure I agree with the characterizations of pastry crusts as "old style" or as "bland" or "somewhat greasy," though this could be the case for specific crusts. The crust I usually make is not greasy, and a greasy crust is a sign of poor worksmanship (usually due to combining fat into the flour). Bland has multiple meanings ("pleasant" for example), but it's generally used as a pejorative; I usually like my crusts. =) Kellen 22:28, 18 May 2005 (UTC)

 * Bland can be good or bad, depending on what you want. A crumb crust made from chocolate cookie crumbs is very much not bland, and completely unsuitable for a chicken pot pie. (well, maybe a pregnant woman would crave such a thing, probably with green olives on top) When you consider how flavorful many of the crumb crusts are, the normal pastry crusts are definitely bland. You could add some herbs and spices to change that of course, but people don't normally do that. AlbertCahalan 22:44, 18 May 2005 (UTC)

 * I think "somewhat greasy" is accurate. A really greasy pie crust is defective of course. If you rub the bottom of a normal pie, you can feel the grease. A good pastry pie crust does a fairly decent job of hiding this, but the crumb crusts are usually a bit better. AlbertCahalan 22:44, 18 May 2005 (UTC)

 * Since all the really old pie crust recipes are pastry, I'm fairly certain that "old style" is also accurate. Let me know if you find a crumb crust recipe that is over a century old. Probably I can find pastry crust recipes that go back several centuries. AlbertCahalan 22:44, 18 May 2005 (UTC)

 * Fair enough. Kellen 22:46, 18 May 2005 (UTC)

 * I will also dispute the description of a pastry crust as "bland, flakey, and somewhat greasy". It is impossible to read this as a positive statement, particularly when followed immediately by fulsome praise for crumb crusts.
 * I will also dispute the claim that "many pies" are made with crumb crusts, because I have consumed very, very many pies in my life, and I have never encountered a crumb crust once outside American cookbooks.
 * It may be the case that "in the USA, many sweet pies" are made with crumb crusts. But this page, as it stands, is far too negative about traditional crusts, and far too biased in favour of sweet pies.  It is totally non-representative of pie crusts in my experience. 81.86.133.45 22:07, 27 March 2006 (UTC)

title: Cookbook talk:Pie Crust


text:
Cookbook:Grandma's Pie Crust

| Desserts | Pie Crust

Ingredients

 * 1 cup (150 g) all-purpose flour
 * ½ tsp (2.5 g) salt
 * 10 tbsp (128 g) solid vegetable shortening
 * 1 egg
 * ½ tsp (2.5 ml) distilled white vinegar
 * 2 tbsp (30 ml) cold water

Procedure

 * 1) Mix flour and salt. Cut shortening into the flour/salt mixture with a pastry cutter, until mixture resembles the texture of tiny peas.
 * 2) In separate bowl, whisk the egg, vinegar and water until well mixed.
 * 3) Drizzle water/egg mixture into flour mixture. Stir with fork until a dough is formed.
 * 4) Gather dough into a ball, flatten into a 10 cm (4-inch) wide disk. Wrap in plastic, and refrigerate 30 minutes.
 * 5) Roll dough into 20 cm (9-inch) circle and fit into a 20 cm (9-inch) pie pan.
 * 6) Line the unbaked pie shell with foil or parchment paper, and fill with dried beans or rice.
 * 7) Bake at 220°C (425°F) until light golden brown (about 15–18 minutes).
 * 8) Cool before filling.

Recipes using this crust

 * Banana Cream Pie
 * Lemon Meringue Pie (American)

title: Cookbook:Grandma's Pie Crust


text:
Cookbook talk:Grandma's Pie Crust

source
This recipe is by Reubenbarton in April 2005. It was attached to the pie recipes before being moved to its own page. AlbertCahalan 23:05, 18 May 2005 (UTC)

50 ml = 10 tbsp??
50 ml is actually about 3.5 Tbsp, or about 10 *teaspoons* but not 10 tbsp.

title: Cookbook talk:Grandma's Pie Crust


text:
User:Fenoxielo~enwikibooks

Hello. I'm a student from the United States who speaks Spanish and I have made some contributions to the Spanish wikibook.

title: User:Fenoxielo~enwikibooks


text:
Radiation Oncology/Stomach

Gastric Cancer

 * Staging
 * Overview
 * Resectable
 * Unresectable
 * Gastric randomized evidence'

title: Radiation Oncology/Stomach


text:
Cookbook:Medlar

Medlars are largish shrubs or small trees. The fruit that grows on them is edible. They were introduced into Greece in 700BC and to Rome in 200BC. They are found in the winter, which is rather unusual. They can only be eaten raw after bletting.

They are sometimes made into jelly and can be used in cheese.

title: Cookbook:Medlar


text:
Cookbook:New England Potato Salad

| Side dishes | US Cuisine

This is a classic New England potato salad. Chopping the potatoes into small pieces allows more surface to be coated and improves the flavor.

Ingredients

 * 3 pounds California long white potatoes
 * 3 hard boiled eggs, chopped
 * 1 medium onion, minced
 * ¾ cup mayonnaise
 * ¼ cup sweet pickle juice (from jar of pickles)
 * 1 tablespoon dried parsley
 * ½ teaspoon celery seed
 * ¾ tablespoon sugar
 * Salt
 * Pepper
 * Paprika

Procedure

 * 1) Cut unpeeled potatoes in half and cook until they are tender when tested with a knife. Do not overcook.
 * 2) Peel the potatoes by scraping them lightly with a knife and cut them into ½ inch (1.25 cm) cubes.
 * 3) Place potatoes in a large bowl and let them come to room temperature.
 * 4) In a small bowl, combine the mayonnaise, pickle juice and sugar and stir until smooth.
 * 5) Add the mayonnaise mixture, minced onion, parsley, celery seed and chopped eggs to the potatoes.
 * 6) Add salt and pepper to taste. Stir lightly to combine.
 * 7) Place in large serving bowl and sprinkle with paprika.
 * 8) Cover and refrigerate until ready to serve.

title: Cookbook:New England Potato Salad


text:
User:Dvortygirl

Dvortygirl can most often be found hanging around the Wiktionary trying to improve things in that project. I may contribute here as I see opportunities, though.

title: User:Dvortygirl


text:
Cookbook:New York Cheesecake

| Dessert | Cake | New York City cuisine

Arnold Reuben, owner of Turf Restaurant at 49th and Broadway in New York City, developed the recipe for New York cheesecake in 1929 after eating a slice of cheese pie at a friend's home.

He altered his hostess’ recipe and eventually developed his own version of cheesecake which relies on cream cheese rather than cottage cheese as most other bakeries did at the time. Reuben then served his new creation in his restaurant which became a hit in no time.

The below recipe makes a firm and heavy cheesecake, nicely flavored with lemon. It is very important to avoid over beating the ingredients in order to avoid cracks.

Crust

 * 5 ounces Barnham and Bailey animal crackers or sweet digestive biscuits
 * 3 tablespoons sugar
 * 4 tablespoons melted butter

Cake

 * 2 ½ pounds softened cream cheese
 * 1 ¾ cups white granulated sugar
 * 1 tablespoon corn starch
 * 3 tablespoons flour
 * Zest of 1 lemon
 * 1 teaspoon vanilla
 * 5 large whole eggs
 * 2 large egg yolks
 * ¼ cup heavy cream

Crust

 * 1) Butter bottom and sides of 10-inch springform pan.
 * 2) Crush animal crackers into a fine powder. Mix with 3 tablespoons of sugar.
 * 3) Add to melted butter and mix with a fork until blended.
 * 4) Press mixture into the bottom and up about one third of the sides of the pan.
 * 5) Refrigerate 1 hour.

Cake

 * 1) Have all ingredients at room temperature.
 * 2) Preheat oven to 475°F.
 * 3) Mix sugar, flour and cornstarch together.
 * 4) Using a wooden spoon, beat cream cheese with sugar mix, zest and vanilla until it is smooth. Do not overbeat.
 * 5) Add the whole eggs and egg yolks, one at a time, beating lightly with wooden spoon after each addition. Do not overbeat as this causes the cheesecake to crack.
 * 6) Gently stir in cream.
 * 7) Pour mixture into the pan. Place pan on cookie sheet to avoid leakage.
 * 8) Bake at 475°F for 15 minutes
 * 9) Lower heat to 225°F and bake for 1 hour
 * 10) Raise heat to 250°F and bake for about 15 more minutes
 * 11) Refrigerate immediately for at least 1 hour, covered with a cloth and cookie sheet (cloth on bottom) until condensation stops forming. Condensation will drip onto the cake if you cover it right away with plastic wrap.

Notes, tips, and variations

 * You may substitute lemon juice for vanilla.

title: Cookbook:New York Cheesecake


text:
Cookbook:Pineapple Teriyaki

| Meat Recipes | Vegetarian

This is a very quick, easy pineapple teriyaki entrée, to be served over rice. It is listed as both meat and vegetarian because it works around the pineapple, veggies, and teriyaki, not the protein. Put the rice on to cook first, and the rest will probably be finished by the time the rice is ready.

Ingredients

 * 2 cups uncooked rice
 * 2 cups water
 * A little salt
 * 1–2 tbsp vegetable or olive oil
 * 2 cups cubed chicken, tofu, or vegetarian "chicken" (usually flavored, pressed gluten)
 * 1 yellow or white onion, diced
 * 1–2 bell peppers (whatever color(s) you prefer), diced
 * 1 can (14–16 oz) cubed pineapple, drained
 * ¼ cup water or reserved pineapple juice
 * 1 tbsp cornstarch (optional)
 * About ¼ cup teriyaki sauce
 * Some sliced mushrooms (optional)
 * 1–2 cloves garlic (optional), minced, depending upon your teriyaki sauce

Procedure

 * 1) Bring the rice, water, and salt to a boil. Cover, turn down the heat, and simmer for 20 minutes. Turn off the heat, fluff with a fork, and let stand for a few minutes.
 * 2) Heat a deep 12-inch pan or wok over high heat. Add the oil, and let it heat up.
 * 3) Sauté everything in the oil, adding the ingredients in the following order, so as to cook heavier items longer:
 * 4) *Chicken
 * 5) *Onion/garlic
 * 6) *Bell peppers
 * 7) *Mushrooms
 * 8) *Pineapple
 * 9) *Tofu
 * 10) Combine the water and cornstarch. Add the teriyaki sauce and the cornstarch mixture to the pan. If using cornstarch, heat to boiling to thicken. Thin with extra water or juice as necessary.
 * 11) Serve over the cooked rice.

Notes, tips, and variations

 * Short-grain white rice is most traditional.
 * Red and green bell peppers stand out nicely against yellow pineapple.
 * Pineapple is often canned in juice, so you may wish to save what you drain.
 * Soy Vay! brand Veri Veri Teriyaki sauce is excellent, if available.
 * You can also cook the rice in a rice cooker.

title: Cookbook:Pineapple Teriyaki


text:
User:Fajro

Hello! I am Fajro, from the Spanish Wikipedia

es:Usuario:Fajro eo:Vikipediisto:Fajro

Browse: Subjects | Categories | Alphabetical Listing | By Completion Status | By Reading Level

Ancient Civilizations – Big Cats – Bugs – Dinosaurs – The Elements – How Things Work – Human Body – Kings and Queens of England – Languages – The Solar System – South America – World War II About Wikijunior >>

title: User:Fajro


text:
User:Luke Bales~enwikibooks

I am Luke Bales Stodola. See my User page on the en:wikipedia. In the past I've written as lbs6380.

title: User:Luke Bales~enwikibooks


text:
Talk:C Programming/Pointers and arrays

I think this article is especially in need of work. I agree with the general sentiment below that the examples are not very helpful; and pointers are conceptually tricky, yet are here approached without substantial introduction to what they really are, or their actual usefulness. Meatnordrink (discuss • contribs) 14:35, 8 December 2020 (UTC)

The example that begins with  doesn't compile for me. That example also probably doesn't belong in an introductory text about pointers. It should probably be substantially rewritten or removed.

Someone wrote:

Declaring an array variable without a size is equivalent to declaring a pointer

followed by a bogus example. This statement is completely untrue. One declares an incomplete array that, unless later completed, is completed at the end of the translation unit with 1 element. It takes up the space of the element. The other declares a pointer, and takes up the space of a pointer. You really should understand this stuff before trying to teach it...

User:207.17.47.140

It's a syntax that comes from C's predecessor B. It's still an accepted syntax for function parameters. Look:

int fn(int a[]){ a++; return *a; }

To really understand all this, I think it is good to describe how C evolved out of B. Without that background, lots of stuff just doesn't make sense. C sometimes gives you a "free" unary & operator when you use an array as a pointer; I'm sure that this is a major cause of beginner confusion. It makes sense once you know that arrays in B were really pointers to arrays. The arrays lost this when the language gained structs, because prior to the C++ invention of constructors there would be no way for the pointer to get initialized to point at the data. Thus we get the weird array-as-a-pointer feature that confuses people.

I think that teaching this should involve:

 * 1) generic language-neutral concepts of arrays, pointers, and strings (no code examples)
 * 2) how B did things
 * 3) the big language change
 * 4) review
 * 5) strings now const. New C99 variable-size array stuff

All through it, the oddities of pointer arithmetic will require frequent reminders. (the whole 42[array] thing, *array, and so on)

AlbertCahalan 04:45, 29 September 2005 (UTC)

Removed the casting of void* to an object pointer type. void* was introduced specifically as a generic pointer type that does not need casting; such casts are a relic from pre-ANSI C when char* was abused as the generic type. Also, removed text that stated that such a cast is necessary. While casting may seem harmless, it can mask the serious problem of forgetting prototypes for allocation functions. In addition, it simply clutters up code. One rarely sees code like "char x = (char)'x';" even though 'x' is an int, for example. The same principle should apply to pointers. -- 67.170.85.37 04:06, 3 January 2006 (UTC)

-

Could anybody explain me that:

typedef int (*MyFunctionType)( int, void *);

I thought typedef is used like that: typedef long int* abc; abc variable1; thx

 * MyFunctionType typedef'ed to be a pointer to a function that takes two arguments (int, void *) and returns an int. Read about the syntax for declaring function pointers in C. --Spoon! 07:22, 25 July 2006 (UTC)

article style
I gotta tell you, this article is really unclear...the problem is changing the way of thinking of someone, especially if they have to wrap their minds around pointers and arrays in quick succession as the article flows. It's especially hard because my background is Java and Perl...

--168.105.118.205 11:10, 30 April 2006 (UTC)

 * I agree. What is this supposed to mean? When returning a pointer from a function, do not to return a pointer that points to a value that is local to the function or that is a pointer to a function argument. WTF? Also, the nonsense examples are distracting. MEANINGFUL examples would be more helpful, even if they're slightly longer. 128.250.37.103 10:14, 23 August 2006 (UTC)

 * It means that, since local variables are deallocated when the function returns, don't return a pointer to any of those variables, or it will be a dangling pointer. Care to rephrase it? --Spoon! 02:05, 1 September 2006 (UTC)

Just as a note, the current external link to a 'pointer cheat sheet' actually goes to a quiz, which I wouldn't describe as a cheat sheet.

Another possibly unclear one: "First one declares a structure having as elements function pointers for the various operations to that can be specified polymorphically." (In #Pointers to Functions.) I assume it means "First one declares a structure [which has elements which are] function pointers for the various operations..." but then it says "... to that can be specified polymorphically." I can't make sense of it unless I assume the "to" was there by mistake, in the sense of "various operations that are to be specified", but I don't know if this is right. 21:23, 12 January 2010 (UTC)

merge
I suggest merging our discussion about pointers into this module C Programming/Pointers and arrays, rather than talk about them here and again in a section of another module C_Programming/Complex_types. --DavidCary (talk) 15:21, 28 March 2009 (UTC)

Is the struct example within scope?
We're leading off with a discussion involving structs, which aren't introduced until C Complex Types. We could either reorganize the two sections so that structs have already been presented, or we could find a different example for this section. I might get around to changing things up before long, but I'd welcome any thoughts on the matter before I have time to Be Bold and whatnot. Ingcake (discuss • contribs) 21:54, 28 May 2015 (UTC)

Pointers and Arrays - example code has extra level of pointer dereferencing
In this example: the last two lines should be:

Please note the removal of the '*' characters from the beginning of the assignment. Those are not needed because In the right-hand form, the '*' _is_ needed.

title: Talk:C Programming/Pointers and arrays


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Template:Language and literature bookshelf

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Talk:European History/Napoleon Bonaparte and the Rise of Nationalism

The content of this page appear to have been copied verbatum from the Wikipedia article on the French Revolution. Please ensure that proper acknowledgement of the fact is provided when revising the material (as required by the GFDL). (Donovan|Geocachernemesis|Interact) 13:07, 19 May 2005 (UTC)

Questions from the module-page
Can someone tell me why napoleon kept one hand in his tunic in almost every photo?

It has been rumored that Napoleon had a tumor in his abdominal area and would constantly touch it. It would be interesting to see if this rumor proves to be valid.

 * It has been said that Napoleon held his hand on his abdominal area, because he had stomache issues. The rumor says it made him uncomfortable.

 * Originally posted on the module page on 08:08, 4 November 2008 by Texican77. -- John N. (talk) 19:15, 10 November 2008 (UTC)

this is way different from what my world history book states.