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# Equations and units for physics

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Hey, I really need some help finding equations and units for physics. As it stands l can hardly remember anything so l decided to create a little forum posting which is a collection of your replies containing units and equations for anybody who wishes to build a more realistic game engine... Write anything even for gravity. Thank you all n GOD BLESS! What l can remember! Work = force * distance! ... blah blah blah... Damn l suck!

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Well, here''s just a few of the equations that are on the AP Physics C equation sheet:

(not that "_" means the next character is in subscript)

v = v_0 + at
s = s_0 +v_0t + (1/2)at^2
v^2 = v_0^2 + 2a(s - s_0)
F = ma (1 kg*m/s^2 = 1 Newton)
p = mv (kg*m/s)
K = (1/2)mv^2 (1 kg*(m/s)^2 = 1 Joule)
U_g = mgh (Joules)
a_c = v^2/r
U_s = (1/2)kx^2 (Joules, k is a N/m constant)

I could go on, but I feel that''s enough If you don''t know what some of those variables means, I''d be happy to explain them, but in case you do, I don''t want to waste my time doing so

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My Physics book called the U_g and U_s you described Ez and Ek. Standing for ''zwaarte-energie'' en ''kinetische energie'', which is Dutch btw. So much for one universal naming convention eh? Luckily all the SI units are international.

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U, according to my book and the College Board, is potential energy, U_g being gravitational PE and U_s being PE of a spring. Some terms, such as these, have multiple variables representing them, unfortunately, and it can lead to some confusion. But what can I do about it?

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Folks,

I suggest that when you post a general equation that you describe what your variable names mean. Some equations are straightforward and common (F=ma and many of the others mentioned above), but there is the possibility of symbol confusion between different textbooks, etc.

Graham Rhodes
Senior Scientist
Applied Research Associates, Inc.

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I appreciate the help nevertheless... Fanx all!

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quote:
I suggest that when you post a general equation that you describe what your variable names mean. Some equations are straightforward and common (F=ma and many of the others mentioned above), but there is the possibility of symbol confusion between different textbooks, etc.

Yeah, that''s why I said I''d explain anything that wasn''t understood. Next time I''ll just explain, though

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If you can''t figure out what the symbols mean, you have no business doing physics. Oh, here''s a good one->

Uo^2 + F *sqrt(moo) = K+

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quote:
Original post by Thrump
If you can't figure out what the symbols mean, you have no business doing physics.

That's a little harsh. Give the less experienced people a break. There was a time when you did not know the symbols, or how to figure them out. Notation can be quite confusing and there is not a problem with beginners needing a little help sometimes. Especially when different sources use conflicting notation.

Here's an example (if the formatting will let me do it). What would you say the following subscripts and superscripts mean?

uin+1=0.5*(uni+1+uni-1)

You may actually know the answer, but perhaps you might agree that this is an example where if you hadn't seen the notation before you would need someone to give you a clue. And this happens to be an equation seen by beginners of a certain type of numerical physics.

Graham Rhodes
Senior Scientist
Applied Research Associates, Inc.

Edited by - grhodes_at_work on December 20, 2001 10:05:30 AM

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Hmm, I just noticed it, but that AP up there was me...

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