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Again, for some odd reason, people...

Apr2211 05:26 AM
ZapperZ

1 
46,973 
I'm having trouble understanding the idea of escape velocity. How can an object escape the gravity of a massive object...

Feb1314 03:54 PM
mpresic

22 
780 
I am reviewing the first chapter of my classical mechanics book (Fetter & Walecka), and in the very first section he...

Feb1314 04:09 PM
mpresic

6 
394 
hey pf!
so when deriving navier stokes we have, from newton's second law, \sum \vec{F} = m\frac{d \vec{V}}{dt} when...

Feb1114 02:27 AM
BruceW

17 
540 
I'm trying to build up some intuition with Gauss's law, calculating the flux through surfaces given certain charge...

Feb1314 09:44 AM
jfizzix

2 
312 
The velocity of any point P of a rigid body in rotation plus translation is \vec{}vp=\vec{}vCOM+\vec{}vp,COM.
Now...

Feb1014 04:10 PM
jbriggs444

5 
303 
Hi, this is my first post on this forum, although ive often refered to many posts for random information, so thanks to...

Feb1514 12:05 PM
Giorgows

6 
296 
Why entropy is highest at lowest energy?
Entropy is disorderness.So low energy means low disorderness.But why it is...

Feb1214 08:28 PM
BvU

16 
452 
Suppose you have an electron moving at constant velocity. This new area that it is moving into initially had 0...

Feb1014 05:29 PM
Khashishi

1 
265 
Why is angular momentum conserved around the bottom left corner in the following set up (see attachment)? The...

Feb1114 03:34 PM
peripatein

2 
220 
hi,
recently i notice that there is a dark border around all the streetlight at night. what is this phenomenon...

Feb1114 05:55 AM
Simon Bridge

2 
200 
1)What is the difference between standing waves,beats and normal interference of any 2 waves ?
2)Is beats in sound...

Feb1214 12:33 PM
olivermsun

6 
376 
Hi
Is this formula all i need for finding the speed i need to tip the trolley?...

Feb1514 08:55 AM
MatsNorway

26 
585 
if a rigid body, lets say a disk,is floating in space and we exert a force outside its center of mass will it rotate...

Feb1114 09:25 AM
freephoton

2 
260 
Let say we have charged conductor M and we know its potential energy function Vm(r) when M is isolated from any...

Feb1214 07:44 AM
UltrafastPED

6 
268 
Hello there,
I was taught:
a = {v^2 \over R}. I substitute v for the speed of the rotating earth at the equator,...

Feb1114 02:37 PM
Jonsson

3 
313 
In kinetic theory a liquid is viewed as an incompressible substance in which the atoms are free to move. I would like...

Feb1514 01:12 PM
CWatters

1 
237 
Hi all
I was just wondering if anyone could help me with estimating error caused by misalignment of an optical...

Feb1314 08:23 PM
Andy Resnick

2 
203 
I've read that if you want light to diffract through a single slit, the slit opening must be equal too or less than...

Feb1314 11:24 AM
Saado

3 
229 
Hello  I'm having a difficult time finding this answer anywhere else on Physics Forums. I'm curious if anyone knows,...

Feb1414 03:48 PM
sophiecentaur

6 
297 
Hi!
I just wonder what's the actual use for
p=nkT≈nE_k
when it comes to plasma physics?
What does p help us...

Feb1614 12:05 PM
rogerk8

6 
326 
For a damped mechanical oscillator, the energy of the system is given by $$E = \frac{1}{2}m \dot{x}^2 + \frac{1}{2}k...

Feb1314 10:09 PM
MuIotaTau

2 
280 
To preface my question, I know it is related to the Gibbs paradox, but I've read the wikipedia page on it and am still...

Feb1614 01:08 AM
jartsa

1 
206 
The standard equation for the damped angular frequency of a normal damped massspring system is ω_{d} =...

Feb1614 04:03 AM
kindlin

5 
375 
Searching through Wikipedia (http://en.wikipedia.org/wiki/File:Resonance.PNG), I found this graph about resonance. I...

Feb1414 03:05 AM
maajdl

1 
165 
I read that for a rotating body the kinetic energy ##E_k = \sum \frac{1}{2}mv^2 = \frac{1}{2}{\omega}^2∑mr^2 =...

Feb1414 07:47 AM
A.T.

3 
196 
One question. In the text
http://locomat.loria.fr/napier/napier1619construction.pdf
author calculate
...

Feb1414 11:23 AM
LagrangeEuler

2 
302 
Would a particle kept in the path of an electromagnetic wave experience a force?
Both magnetic and electric field are...

Feb1614 10:47 PM
nasu

5 
243 
why should we use a convex lens to focus the rays at the point on the screen.why is at an angle instead of being...

Feb1614 04:39 PM
Philip Wood

8 
300 
The total energy of the magnetic field in the matter is \frac{\mu H^2}{2} , I want to calculated the energy that is...

Feb1614 11:33 AM
DrZoidberg

3 
299 
Suppose we have a infinite current sheet of surface density \sigma and apply Ampere’s law to find the magnetic field....

Feb1514 08:03 AM
DaleSpam

1 
186 
So Rayleigh scattering says that higher wavelengths of light are scattered more than lower ones  but why don't we...

Feb1514 01:44 PM
Jbeats245

2 
243 
why do the atoms in excited state alone could emit line spectra?can't they emit when they are not in gaseous state?
...

Feb1614 04:16 PM
Drakkith

1 
369 
Hello,
I was wondering, do the Lee/Kesler correlations apply at the saturation line for vapor/liquid equilibrium? I...

Feb1514 10:43 PM
Maylis

0 
206 
So, I asked myself the question, "why does the earths force of gravity effect us so dramatically on the surface of the...

Feb1614 04:05 AM
kindlin

3 
228 
What will be the degrees of freedom of a ''Connected pair of compasses''?

Feb1714 12:45 AM
AbhiFromXtraZ

6 
259 
From what I understand, an atom generates an electromagnetic field which exerts energy on objects and this...

Feb1614 10:42 AM
mal4mac

2 
226 
Suppose you have a sphere (sphere A) with net positive charge 2Q. A conducting spherical shell (sphere B) of inner...

Feb1614 02:39 PM
VishalChauhan

2 
227 
I am studying Laplace's equation in my electrodynamics course (using griffiths intro to electrodynamics). I am...

Feb1614 10:56 AM
dauto

3 
243 
I've been having a problem with the sign of potential. Electric potential as I know it is defined as V =...

Feb1714 05:57 AM
Philip Wood

7 
309 
Say, i have two concentric shells,each carrying a different charge.If i connect an ideal, resistance less wire between...

Feb1714 04:27 PM
Nugatory

10 
417 