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

Apr2211 05:26 AM
ZapperZ

1 
47,831 
how much time does it takes to heat a container or diameter 20 cms

Nov2309 01:06 PM
Integral

1 
809 
F=\nablaV
i cannot fully understand it ,though i can deduce it in some ways.
i also want to know why potential...

Nov2309 09:34 AM
fluidistic

1 
739 
I can't prove the Newton's third law.
Please tell me how to prove the Newton's third law.
Thanks.

Nov2309 09:03 AM
YellowTaxi

7 
5,304 
In the beginning scene of the film One Eight Seven, Samuel Jackson's character has one of his students hold a bicycle...

Nov2309 05:09 AM
sharpnova

2 
1,108 
Say you had two tanks of significantly different temperature water (Say 25 deg Celsius, and 70 degrees Celsius) and...

Nov2209 10:36 PM
MaxwellsDemon

3 
2,615 
Voltage = Charge / Capacitance.
This assumes that the capacitor has +Q charge on one side and Q charge on the...

Nov2209 09:34 PM
fluidistic

3 
995 
so here are my questions:
Does a single capacitor take longer to discharge than two capacitor is series? Why?...

Nov2209 07:56 PM
chanderjeet

5 
7,397 
For an integrable Hamiltonian system with N degrees of freedom, there exist N commuting (the poisson bracket of any...

Nov2209 07:17 PM
jojo12345

0 
730 
I have a question regarding the similarity between the BiotSavart law and the equation that gives the magnetic field...

Nov2209 05:37 PM
bitrex

0 
509 
When we have electron and proton . Both electron and proton have electric field and electric field has energy.Inside...

Nov2209 01:38 PM
DaleSpam

4 
944 
Dear All
I have a question about tension in a mass system with pulleys.
http://i48.tinypic.com/vpc1vl.jpg
The...

Nov2209 12:24 PM
Doc Al

2 
1,047 
im having trouble find out when exactly is the intial speed and final speed when dealing with momentum....for example:...

Nov2209 12:10 PM
Doc Al

1 
700 
When I put a near 0°C water in a glass which is at room temperature (around 2530°C), some water in air (humidity)...

Nov2209 10:18 AM
fluidistic

2 
2,066 
Hi!
I'm trying to build a "pump" pushing water a few meters up of the river bank, and wondered if I could do it...

Nov2209 09:14 AM
Leafhill

21 
8,719 
Hello,
My 7th grade son has selected a science project which requires to find the impact of two toy cars...

Nov2209 08:15 AM
xxChrisxx

3 
5,089 
can anybody tell me .the concept of rigid Rotator.Kindly let me know the idea.

Nov2209 04:19 AM
tinytim

1 
811 
if a cylinder rolls down and incline without slipping
then i decrease the coefficient of friction and it does slip...

Nov2209 12:47 AM
rcgldr

15 
1,827 
I am usually bad with calculations, so please help me out.
It's not a homework, merely my interest...
So, lets say...

Nov2109 10:17 PM
rcgldr

3 
1,364 
In the photoelectric effect, if you have a frequency above the threshold frequency, electrons are ejected with greater...

Nov2109 09:56 PM
MrOriginal

0 
461 
Gravitational force is divided by distance squared.
What is the equivalent divisor for a fixed bar magnet?
Thank...

Nov2109 09:21 PM
jtbell

4 
5,628 
So I'm relatively new to the world of physics (Junior in high school) and I'm having a little trouble sometimes with...

Nov2109 08:52 PM
1st2fall

2 
688 
If a cylindrical tank of radius 1m rests on a platform 5m above the ground. Initially the tank is filled with water up...

Nov2109 12:13 PM
jeedoubts

2 
607 
Why is the trajectory of a rocket always parabolic if a rocket launches straight up in the air perpendicular to the...

Nov2109 12:09 PM
IPhO' 2008

4 
4,017 
As we know, Newton's Law of Gravitation is
\
and Coulomb's law is
\
We know from comparing the...

Nov2109 11:22 AM
D H

1 
1,755 
When a sphere radius r has a velocity v in a liquid .It will has a drag force exerted on the sphere. The drag force is...

Nov2109 10:16 AM
Redbelly98

5 
2,238 
Can you tell me how to find CG. point.
thank you.

Nov2109 08:48 AM
Redbelly98

8 
2,805 
I try to clearify it as much as I can, and I greatly appriciate the given answers.
Suppose that we have a rigid...

Nov2109 12:46 AM
bluelava0207

2 
1,237 
We can use B = \frac{\mu}{4\pi} \frac{q}{r3}
when v << c (c is a speed of light) but if v is nearly to c we can't...

Nov2009 11:02 PM
IPhO' 2008

3 
660 
How do you see the whole of milky way if we are in it?

Nov2009 07:23 PM
turbo

3 
979 
I solved the problem below using Einstein's Equivalence Principle, or "elevator experiment," and I easily find an...

Nov2009 05:42 PM
bluelava0207

0 
601 
I am working on a simulation of a ball moving in a complex 2d environment. I am looking for a single physics model...

Nov2009 03:52 PM
StefenRoebke

15 
2,057 
What is image charge? and how we can use image charge?
thank you so much.

Nov2009 12:15 PM
Bob S

5 
3,730 
I am having two metal sheets which are curved and fitted on the outer sides of a pipe. A 9V pottential is applied to...

Nov2009 09:00 AM
mathew086

2 
1,028 
A charge q has a velocity v in the magnetic field B if v is nearly to velocity of light.
Can we use F = qvB....

Nov2009 06:28 AM
clem

3 
4,998 
Attention FORUM ADMINISTRATOR
Request regarding my thread "Energy Converted to Electricity"
I seem to have asked...

Nov2009 05:44 AM
russ_watters

2 
2,354 
Heinrich Lenz postulated in 1834 the following law;
"An induced current is always in such a direction as to...

Nov1909 11:12 PM
Born2bwire

5 
2,833 
Hi there,
Having a bit of trouble working something out for a lab experiment at uni  not sure if this really...

Nov1909 08:29 PM
Redbelly98

1 
2,386 
Can a thermal imaging camera detect a body that is cooler than the detector? Or does the temperature of the detector...

Nov1909 06:01 PM
mgb_phys

1 
1,078 
The Law of Biot and Savart Law tells us how to find a differential form that generates the first de Rham cohomology of...

Nov1909 05:06 PM
wofsy

2 
1,355 
So I'm sort of confused by voltage and I hope these will clear it up for me;
1) Why can parallel circuits only have...

Nov1909 09:15 AM
sophiecentaur

1 
540 