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

Apr2211 05:26 AM
ZapperZ

1 
45,988 
This relates to the extension of a uniform crosssection, homogenous, ideal wire which extends within the proportional...

Apr714 10:01 PM
kirakun

6 
267 
I am currently working on an experiment with piezoelectricity and was wondering how I would measure the force applied...

Apr714 05:38 PM
themadquark

3 
227 
Hi,
I was wondering what the frequency of a photon is according to maxwell's equations. Does the...

Apr714 05:04 PM
Drakkith

24 
943 
Hi! I have been studying AC generators. I am confused about why there is no current when the armature is...

Apr714 02:07 PM
jtbell

4 
230 
I have a quick question regarding causality in SR and some specific examples. Collision between two bodies is one of...

Apr714 11:03 AM
DaleSpam

10 
568 
According to Faraday's Law a changing magnetic field induces an electric field, an example of this is if you have a...

Apr714 08:18 AM
nasu

3 
209 
Sorry, but this will be a long post.
This isn't homework, I'm reviewing physics after many years of neglect.
...

Apr714 06:00 AM
jbriggs444

8 
473 
Imagine I am standing but not moving forward/backward, but I am rotating my body about my own axis. Now imagine if I...

Apr714 12:20 AM
UltrafastPED

1 
188 
I am not well versed in complex physics (I've taken honors physics in High school) so any help I can get with simpler...

Apr614 11:08 PM
WannabeNewton

6 
322 
How come a spring with applied weight of 1000 g goes down 9.8 cm but the same spring with applied weight of 500g goes...

Apr614 08:16 PM
jtbell

2 
198 
Consider a solenoid of length l, no. of turns N, n = N/l, area A, and negligible resistance. In its middle is placed...

Apr614 04:17 PM
rude man

8 
381 
http://www.physicsforums.com/attachment.php?attachmentid=67782&stc=1&d=1395173030
Consider the following setup (see...

Apr614 01:26 PM
DaleSpam

54 
1,670 
Greetings,
I fell upon a certain question and it seemed that no matter what I did I was unable to solve it. I wished...

Apr614 10:08 AM
nasu

11 
376 
Given a system's Lagrangian, How can we calculate the equilibrium points corresponding to the system? also how can we...

Apr614 08:12 AM
dauto

1 
171 
Greetings,
I was thinking about bouncing a tennis ball against a wall and how its momentum and kinetic energy would...

Apr614 02:10 AM
drichard

4 
181 
Hi, does somebody know a good website with many exercises about Lagrangian/Hamiltonian mechanics? And I mean problems...

Apr614 01:47 AM
UltrafastPED

1 
199 
Suppose we have two colinear strings under tension, attached far away, and with propagation speed v. Let the strings...

Apr514 03:38 PM
Spinnor

0 
233 
As I understand it, The intensity and extensive thermodynamic system parameters can only be internal parameters. The...

Apr514 01:38 PM
yuiop

6 
324 
I was following along in my Thermodynamic textbook and began playing with some definitions. In the following...

Apr514 07:24 AM
UltrafastPED

1 
197 
Hi
I am using Simple Harmonic Motion in a Matlab/Simulink model. Instead of using a motion for a simple pendulum, I...

Apr514 04:09 AM
T2theB

1 
265 
Momentum of a body can be constant while it accelerates? I mean if velocity increases while mass decreases...

Apr514 01:36 AM
Michael_25

8 
360 
(This is not a homework problem, but is just something I'm curious about.)
If two rocks with different momentum...

Apr414 10:48 PM
cjl

16 
363 
So if I slowly pull the A string first B string will tear apart... Cause the A string will expand and it will pull the...

Apr414 05:31 PM
Ezio3.1415

2 
183 
Hello,
I'm trying to make my own physics engine. I've already made one with momentum and an very easy
collision...

Apr414 01:11 PM
craigi

5 
359 
Hi
I have calculated angular acceleration which changes with time. I also have a moment(torque) which also changes...

Apr414 09:36 AM
james6008

4 
286 
A homogene rod with length "l" is placed vertically, and a nail is stabbed on the top of the rod (now the rod has an...

Apr414 06:43 AM
Andreas

0 
223 
I have just watched a MythBusters episode investigating whether a concrete glider could fly. They conclude that it was...

Apr414 02:29 AM
A.T.

14 
368 
Recently, Facebook suggested solar powered drones could be used to provide internet coverage in remote areas and they...

Apr314 03:02 PM
yuiop

5 
305 
EDIT : solved, thanks :)

Apr314 08:57 AM
CWatters

1 
161 
Is it possible for a magnetostatic field to exhibit vector circulation when no current ( free, bound or polarization )...

Apr314 12:58 AM
UltrafastPED

6 
319 
hey pf!
so i have a small question when deriving the navierstokes equations from newton's 2nd law. specifically,...

Apr214 11:06 PM
joshmccraney

6 
235 
Hi,
I need help with the following equations.
n = r/r (unit vector in r direction)
v =d r/dt = dr/dt n +...

Apr214 07:03 AM
knockout_artist

4 
286 
If you stop cooling a resistor and stop current simultaneously then what happens to the temperature of the resistor in...

Apr214 03:05 AM
256bits

2 
230 
I'm wanting to get the time it would take a vehicle to travel a 1/4 mile coming out of a corner in the ideal world. By...

Apr114 06:06 PM
RedRook

17 
517 
I am trying to use thermodynamics manipulations in order to find \partialP/\partialV (at constant entropy) I tried...

Apr114 04:35 PM
rude man

1 
229 
I am doing a final year project, my Prof gave me 2 prism.
He wants me to do so:
A white laser is shot on a prism...

Mar3114 10:18 AM
athrun200

5 
281 
If I have a pair of coils connected in an antihelmholtz configuration, with current flowing oppositely in both, and I...

Mar3114 09:49 AM
UltrafastPED

16 
346 
On the 2012 AP Physics C Mechanics test, I got confused by the sign conventions for torques on question 3....

Mar3014 11:59 PM
Simon Bridge

1 
215 
I was wondering where the derivation of the formula
Group Velocity = Phase Velocity + K(dVp/dK)

Mar3014 01:55 PM
UltrafastPED

1 
201 
What happens To the force between 2 charges if a metal sheet or a dielectric sheet is kept in between the two charges...

Mar3014 01:52 PM
UltrafastPED

1 
193 