
Before posting anything, please review the Physics Forums Global Guidelines.
Again, for some odd reason, people...

Apr2211 05:26 AM
ZapperZ

1 
46,914 
Hey, currently I am a high school graduate going into college in the fall, but that isn't why I am here. There has...

Jun2414 11:08 AM
berkeman

5 
549 
I was thinking the other day and it looks like I need feedback if I am being stupid or crazy.
My question is quite...

Jun2414 10:05 AM
mr.smith

14 
712 
If heat flow is the momentum change from a faster moving atom or molecule to a slower moving one, and momentum is mass...

Jun2414 04:42 AM
NicholasB54

2 
353 
I am attempting to work through a paper that involves some slightly unfamiliar vector calculus, as well as many...

Jun2314 09:32 PM
Matterwave

1 
351 
I promise this isn't homework, it's actually for my research :P Here goes:
When two bodies are in contact and...

Jun2314 09:17 PM
97313

4 
442 
Can I use Fleming's right hand rule to determine the direction of current when a magnet is moved into a coil(s) of...

Jun2314 04:46 PM
Philip Wood

10 
523 
Hi everybody, I'm new at the forum. I've started learning physics on my school last year.
I've a question.
How...

Jun2314 11:32 AM
fgp40

6 
378 
Hello everyone,
In order to define the eulerian rate deformation tensor, one should first express...

Jun2314 04:29 AM
trabo

4 
293 
Please, tell me really simply from the viewpoint of molecular physics... Why is liquid having a smaller density on...

Jun2214 03:09 PM
Oomph!

8 
327 
I am little experience of physics so please be patience with me, This is my first post of this great internet forum.
...

Jun2214 02:36 PM
UltrafastPED

1 
262 
Hi,
Attached is the equation relating the vibration of a sphere radius R, to the pressure field it generates. ρ is...

Jun2214 11:50 AM
DeltaČ

11 
367 
Turbulent fluid has more energy (mass) than laminar fluid?

Jun2114 02:26 PM
Abel Cavaşi

2 
222 
Hello.
I have a question... I think that you know the experiment with pepper and soap.
(you put water on plate, than...

Jun2114 01:13 PM
CWatters

1 
194 
http://imgur.com/QhYG54l
The image seems to be not showing here is the link : http://imgur.com/QhYG54l
What...

Jun2114 12:03 PM
Coffee_

13 
333 
Hi, sorry if this is in the wrong forum but 2 Quick hopefully simple questions about Poynting vector and EM waves.
...

Jun2114 10:17 AM
tim9000

7 
363 
This is a very basic question.
We know for a particle moving under constant acceleration we can use both the...

Jun2114 07:44 AM
BruceW

11 
386 
E =  grad*phi  1/c (dA/dt).
phi is the scalar potential, and is given. How do I calculate the vector potential = A...

Jun2114 07:20 AM
BruceW

2 
199 
If a moving point mass collides with a point mass at rest then you can find the resulting velocities by conservation...

Jun2114 03:44 AM
Orodruin

6 
284 
Hello
WARNING: Some people may find this post a little gross.
I observed something today that I didn't know...

Jun2014 08:15 PM
Chestermiller

2 
209 
Hello there,
I am having a discussion with a coworker about a pressure drop test. I have two different 'boxes'...

Jun2014 12:47 PM
mfb

3 
229 
Hello guys,
I want to study the temperature evolution of a gas in a vessel from 200 bar to 20 bar. I made the...

Jun2014 10:02 AM
Andrew Mason

4 
335 
Hi, I am trying to derive the Lorentz force law in the following form:
q \frac{dw^\mu}{d\tau} = q w^\mu...

Jun2014 02:34 AM
vanhees71

1 
201 
1. I found this diagram on book but there weren't any description.can someone tell me, what its trying to tell...

Jun1914 01:20 PM
jbriggs444

5 
477 
Hi all,
I've been trying to understand how to calculate the elastic energy of a deformed object. For example, if I...

Jun1914 02:24 AM
UVW

3 
305 
When a wire is placed in a magnetic field and current flows in that wire work is done on the wire and be calculated:
...

Jun1814 01:04 PM
DaleSpam

20 
693 
If work ##W = \Delta E = \int_{s} \vec{F} \cdot d\vec{s}##, so work can't be ##\frac{dW}{d\vec{s}} = \vec{F}## like is...

Jun1814 12:54 PM
DaleSpam

12 
466 
Does pV = \dfrac 1 3 N m \left(c_{rms}\right)^2 apply in containers that aren't cuboids? The derivation I have seen...

Jun1814 12:53 PM
Philip Wood

2 
270 
Hey guys,
I understand why the theorem describes the relationship between the lengths of the sides of a right...

Jun1814 08:33 AM
RyanXXVI

8 
435 
I am going to make a power supply. I understand the smoothing capacitor and the fullwave bridge rectifier.
I am...

Jun1814 04:01 AM
enorbet

12 
413 
Hello.
I have a question.
I have two glasses  one is full, one is empty. And I will take a long paper towel to them...

Jun1714 03:14 PM
A.T.

1 
183 
So I understand that to calculate the intensity a distance d away from a lightbulb you would treat the lightbulb as...

Jun1714 02:37 PM
dimitri151

1 
171 
I'm studying classical mechanics and I'm stumbling in the quantity of differential identities.
Being S the action,...

Jun1714 05:39 AM
Vanadium 50

3 
361 
Hi all,
This is Newton's universal law of gravitation:
F = GMm/r2, where r is the distance between the centre of...

Jun1714 05:32 AM
UltrafastPED

5 
276 
1. Static friction cannot do work (correct?). Yet that is the only external force acting on an accelerating bicycle. ...

Jun1614 05:07 PM
A.T.

71 
1,524 
Hi guys. Consider the problem of calculating the multiplicity (phase space volume) of N hard sphere gases each of...

Jun1614 02:00 PM
Jano L.

5 
345 
If ##V_{BA} = P_B  P_A## (where V is the voltage and P the potential) so, ##V_{AB} =  V_{BA}##. The same ideia for...

Jun1614 12:43 PM
DaleSpam

1 
176 
I read that there are polarizing and non polarizing beam splitters.
Are there adjustable bleam splitters between them?

Jun1614 03:52 AM
naima

3 
198 
Hello everyone!
I was reading the following review:
...

Jun1514 08:47 PM
586

6 
469 
The derivation of Planck's law in my textbook begins with the assumption that the energy of an oscillator with...

Jun1514 07:33 PM
Andrew Mason

1 
203 
Hi,
The focal length of the PlanoConvex lens as calculated by the lens maker equation: Does it work when light...

Jun1514 04:18 PM
bgq

2 
250 