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

Apr2211 05:26 AM
ZapperZ

1 
47,829 
Can light travels without electromagnetic field ?
Thanks

Jun3014 12:20 PM
Quarlep

7 
1,504 
Hi! everyone...
I'm a building a standing frame for disabled children, the structure in elemental form is shown in...

Jun3014 08:11 AM
Harsh188

2 
984 
I notice on this page at Rice University that regarding Newton's 3rd law it says that...
Surely this is a...

Jun3014 04:49 AM
A.T.

1 
698 
Hi
Let a classical particle with unit mass subjected to a radial potential V and moving in a plane.
The...

Jun3014 04:24 AM
vanhees71

3 
760 
I really want to know if there is a difference between the force from the first impact of water and the force from...

Jun2914 08:44 PM
TumblingDice

10 
1,547 
I am looking for an equation that correlates material failure and collision speed;
so that I can better understand...

Jun2914 07:34 PM
caz

2 
776 
I have problem undestanding newton's III law. When i press the wall the wall react with the same force on me but as I...

Jun2914 04:43 PM
ultrauser

42 
4,028 
Hi  I am currently working on a paper verifying some thermal hydraulic code against experimental test data for...

Jun2914 03:59 PM
Q_Goest

2 
811 
I am working through Leonard Susskinds 'the theoretical minimum' and one of the exercises is to show that...

Jun2914 03:36 PM
WannabeNewton

1 
765 
If the speed of light is changing, does this mean that the permattivity and/or permeability are dynamically changing...

Jun2914 09:38 AM
athosanian

6 
1,378 
Take a closed system of particles. Each has it's own mass, but that's really about it for the sakes of this argument....

Jun2714 05:51 PM
Jano L.

6 
815 
Hey everyone,
A meager pea brain (me) is in need of some help from you fine physics gentlemen.
This is a concept...

Jun2714 03:24 PM
Volkr16

3 
662 
As it's stated in Newton's law of gravitation, every object with mass attracts all other object with a force which...

Jun2714 02:57 PM
Matterwave

12 
1,262 
One page 5 in Landau & Lifshitz Fluid Mechanics (2nd edition), the authors pose the following problem:
The...

Jun2714 10:57 AM
mSSM

6 
788 
Recently on an aquarium related forum, I called out someone for making what I considered to be an outlandish claim and...

Jun2714 09:19 AM
Overflowing

17 
3,003 
If a blackbody is in equilibrium with the surrounding electromagnetic field, the power emitted by the surface of the...

Jun2714 04:54 AM
mediray

5 
875 
Hello,
In CFD computation of the NavierStokes Equation, is stress tensor assumed to be symmetric?
We know that in...

Jun2714 04:52 AM
vanhees71

2 
779 
Not really sure where this belongs... But here goes:
If you illuminate a photo diode it generates a current because...

Jun2614 02:05 PM
itaischles

2 
728 
I'm sorry, I wasn't exactly sure where to put this question but this section is probably my best bet. I'm basically...

Jun2614 01:59 PM
itaischles

1 
682 
Hello everyone, I've been having trouble with the following reasoning for a while. The book I use for learning is...

Jun2614 08:00 AM
jameswhite

5 
886 
Hi,
When we want to solve the NavierStokes equations coupled with the conservation of mass for incompressible...

Jun2614 01:11 AM
Zoli

10 
1,004 
In feynman's description for the ratchet pawl system he gets the efficiency for the system to be same as he efficiency...

Jun2514 09:12 PM
Simon Bridge

1 
499 
Take a hypothetical object with an infinite density (purely so that a particle can get incredibly close to it)....

Jun2514 04:02 PM
Arnoldas

1 
526 
Hello everybody,
I'm studying classical electrodynamics and I'm having a difficulty grasping the concept of EMF....

Jun2514 02:46 PM
cabraham

9 
700 
I can't figure out why the length the a pipe (L) increases the change in driving pressure with respect to this law:
...

Jun2514 11:49 AM
Philip Wood

4 
610 
The seawater in deep oceans have a density of 1050 kg/m³ or so.
The density of air is about 1.3 kg/m³, about 800...

Jun2514 10:35 AM
Chestermiller

14 
852 
Didn't seem to have much luck on the actual reasoning with this elsewhere.
A regular pinhole projects an image, and...

Jun2514 09:59 AM
UltrafastPED

1 
428 
http://i.imgur.com/wPdNsUI.png
In the solution , it says we have dr/dt= V (polar coordinates)
How? i can't see how...

Jun2514 08:48 AM
Andrax

3 
452 
We know that the magnitude of tangential component of acceleration is,
atangential = dv/dt (where v is speed)
So...

Jun2514 05:08 AM
dean barry

19 
1,693 
Hello.
I know what is diffusion... chemical process when molecules from a material move from an area of high...

Jun2414 01:28 PM
marcusl

1 
454 
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 
596 
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 
744 
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 
381 
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 
388 
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 
516 
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 
573 
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 
415 
Hello everyone,
In order to define the eulerian rate deformation tensor, one should first express...

Jun2314 04:29 AM
trabo

4 
315 
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 
349 
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 
279 