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Again, for some odd reason, people...

Apr2211 05:26 AM
ZapperZ

1 
45,612 
can anyone proove "kelvin plank" statement of second law of thermodynamics or atleast show that it is always followed...

Dec3107 07:47 AM
sadhu

4 
3,268 
Hi all,
I'm posting here because I see an apparent paradox between what intuition and equations tell me. I'm sure...

Dec3107 02:11 AM
animalcroc

7 
2,526 
Hello, I was recently browsing through on of my physics books, and I came upon the following statement:
"Newton was...

Dec3007 06:19 PM
Integral

2 
1,884 
So.. we've got a 2D crystal, corresponding an infinite square net with +e0 charges in each one (see the atached...

Dec3007 04:40 AM
Istvan

2 
3,245 
why is there a factor of 1/4 in front of the two tensors? Is it formulated that way for convenience?

Dec2907 11:29 PM
Parlyne

1 
3,844 
According to Noether's Theorem, for every symmetry of the Lagrangian there is a corresponding conservation law. For...

Dec2807 10:58 PM
Rainbow Child

1 
1,931 
Can anyone tell me where the 4*pi comes from in coulomb's law? I know the law is often compared to netwon's law of...

Dec2807 07:04 PM
rbj

7 
9,092 
Hi
I need to prove Maxwell's second equation \nabla\bulletB=0
I tried few things, but never came with result... and...

Dec2807 06:23 PM
ZapperZ

14 
3,541 
a problem.....pls check..
imagine theres a horizontal planeA bove which the effects of gravity are not felt. any...

Dec2707 01:19 PM
Himanshu

50 
8,966 
Hi folks, I have a problem that I am trying to figure out that I hope you can help me with. I don't want to be spoon...

Dec2607 10:28 PM
shiftless

4 
1,734 
Hello, is it possible to figure out how much force in newtons is created when a compressed gas expands?

Dec2607 03:55 PM
russ_watters

6 
7,076 
we know that during inelastic collision momentum remain conserved but kinetic energy of system does not
some part of ...

Dec2607 03:19 PM
Shooting Star

12 
2,417 
do gravitational field lines always need to be straight, cant they be just curves
if yes then please tell an...

Dec2607 12:56 PM
sadhu

2 
1,635 
What does the term "Action" means in physics?

Dec2607 12:04 PM
belliott4488

9 
1,993 
how does a transformer work?

Dec2607 01:00 AM
rbj

5 
3,916 
Does anyone know of an experiment that shows that the electrostatic and/or magnetostatic forces have a finite speed,...

Dec2607 12:46 AM
rbj

2 
1,768 
When they say K=1/2mv^2 does K mean the change of kinetic energy? because Wtotal= the change of kinetic energy...

Dec2507 10:59 PM
sadhu

2 
1,768 
hello all, i've been researching a bit of info on lens optics (image propagation mostly), but have only found...

Dec2507 08:27 PM
infamous_Q

0 
1,982 
Hi all,
I was giving a class on dilatation and I have proposed to the students a problem where two pieces of wire...

Dec2507 06:16 PM
DaTario

30 
3,503 

is it true that when the net force...

Dec2507 01:54 PM
Shooting Star

2 
1,832 
I want to find a solid argument why entropy always increases and even more important why it is
S=\sum_i p_i \ln p_i...

Dec2507 08:09 AM
Gerenuk

0 
1,795 
The Ampere's Law is \nabla \times B = \mu J and Gauss's Law is \nabla \cdot E = \frac{1}{\epsilon} \rho
Since J...

Dec2407 06:17 PM
G01

5 
2,219 
Hi! I am new user to this forums and on the start I have one question:
"If I increase the speed of the electrons,...

Dec2407 08:16 AM
Physicsissuef

2 
2,590 
Hello experts,
I hope you can help me with the following problem.
There is one huge pipe (diameter about 3 meters)....

Dec2307 04:30 PM
LURCH

7 
1,236 
Hi all,
I'm a bit confused about ferromagnetism (and I've come to realize that I'm not the only one)! I'm currently...

Dec2207 08:51 PM
marcusl

1 
2,545 
I am trying to figure out a problem. When hydrogen and nitrogen are mixed, the entropy of the gas tends to mix them...

Dec2107 09:43 AM
lilrex

7 
1,376 
if there is a decrease in pressure at constant temperature will there be an increase in entropy?

Dec2007 04:31 PM
Andrew Mason

7 
5,635 
Hi there.
I'm having a problem explaining the physical meaning of the symbols in the equation for an underdamped...

Dec1907 10:06 PM
Cyrus

4 
1,708 
Hey Guys,
I know that this has been posted before, but mine is slightly different.
Our instructor only provides:...

Dec1907 08:16 PM
pervect

6 
13,155 
Can entropy change be zero for a closed system in an irreversible process? If yes under what conditions? Thanks!

Dec1907 12:02 PM
Shooting Star

2 
8,881 
Why do all rays coming from far off distance from a source(may be planar)... converging at a point need to travel the...

Dec1807 12:56 AM
pardesi

4 
1,058 
I am reading Introduction to Mechanics by Kleppner and Kolenkow. I am now reading the articles dealing with...

Dec1707 11:27 AM
arildno

5 
2,827 
Please see this link first: http://en.wikipedia.org/wiki/Precession#Classical_.28Newtonian.29
How do they get to...

Dec1607 06:27 PM
JolleJ

10 
4,263 
having problems trying to understand and derive the equation for intensity in the doubleslit interference pattern. ...

Dec1607 05:28 AM
St_LightStorm

42 
4,444 
My teacher asked us too prove that Hamiltons principle proves that newtons equations of motion hold for N particles....

Dec1607 12:00 AM
frenchyc

4 
2,008 
Voltage = Current * Resistance
Power = Current^2 * Resistance
Magnetic field magnitude of a solenoid = magnetic...

Dec1507 06:39 PM
DaleSpam

5 
2,984 
I conjecture that only spherical symmetric mass distribution can produce radial gravitational force field (according...

Dec1507 04:22 PM
mma

11 
3,121 
Bulb with volume of 5 liters is filled with nitrogen n = 3 molls. The bulb is set in space, the bulb cracks and the...

Dec1507 12:10 PM
Privalov

25 
2,067 
In the chapter on radiation (Chapter 11), Griffiths notes that an electric monopole does not radiate, but also that a...

Dec1507 06:14 AM
Shooting Star

1 
1,158 
Hi all,
If we take the integral of tau (the resultant torque) times the angular displacement theta, with respect to...

Dec1407 09:17 PM
Shooting Star

18 
2,524 