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

Apr2211 05:26 AM
ZapperZ

1 
47,867 
The problem gives me a mass at the top of an inclined track. the track is not linear but curved and the bottom of the...

Sep1108 01:46 PM
lightning208

2 
1,071 
I was asked this recently and the only explanation I could come up with was that the Earth is oblate and the...

Sep1108 04:11 AM
D H

2 
2,211 
In one dimentional cases, will the velocity of a particle tend to the terminal velocity unregardless of any...

Sep1108 02:12 AM
Lucien1011

2 
1,324 
Follow the below four steps to amuse yourself
1) Take a semicircular wire. You know that its COM is at (0,2R/\pi)....

Sep1008 08:08 PM
matematikawan

5 
2,396 
A magnet surrounded by copper wire spins generating a A/C current down a wire for as long as it spins. Are electrons...

Sep1008 08:06 PM
russ_watters

9 
1,505 
I was learning a bit of centrifugal/centripetal forces, and then I asked myself. If at the equator, the Earth rotates...

Sep1008 07:26 PM
matematikawan

5 
19,816 
I am currently a grad student. Part of my PhD work will be to formulate a mathematical model of a manufacturing...

Sep1008 02:22 PM
engineer23

0 
2,291 
I'm driven crazy by this question these days. so here it goes.
Consider a ball sliding on a frictionless surface with...

Sep1008 09:20 AM
atyy

15 
2,256 
i've been trying to get the exact definition of a banked angle but so far, i've gotten nothing so i would like...

Sep908 10:29 PM
Antenna Guy

1 
2,030 
Start with:
$\frac{d}{dt}$ $\frac{dL}{dx"}$ = $\frac{dL}{dx}$
(d/dt)(dL/dx") = (dL/dx)
Now intruduce three...

Sep908 08:44 PM
alejandrito29

0 
673 
how can we say that torque is equal to power / angular velocity though we know that torque is equl to I x (change of...

Sep908 04:53 PM
russ_watters

4 
6,125 
We may say a process is adiabatic if it occurs fast enough such that no heat is exchanged from the system.But we also...

Sep908 09:14 AM
Count Iblis

4 
3,258 
The relation between the angles for which the minima occurs for a Fraunhofer diffraction(parallel rays, large...

Sep908 07:15 AM
Antenna Guy

8 
1,899 
I'm a biochemistry major entering my junior year. After completing the requisite general physics course, I found that...

Sep908 12:35 AM
atyy

4 
5,017 
Hi,
I have read that Thermal Conductivity means: “The thermal conductivity of a substance is the quantity of heat...

Sep808 09:38 PM
Kasper_NYC

1 
1,957 
Please help me to know moment, moment of inertia (mass,area,polar) and difference between them.
How can we obtain...

Sep808 08:50 PM
sri.karmarkar

0 
543 
Not sure if this is the right place to ask this, but why is the average shear rate in a cylinder 2/3rds the shear rate...

Sep808 06:49 PM
physics_forums

0 
1,202 
I'm a new teacher to E&M and confess I was a lowly Chemistry Major who needs some help.
A proton and a particle of...

Sep808 01:23 PM
clem

6 
3,030 
according to the figure attached below , do we have a coriolis acceleration on the slider and why ?
why cant we...

Sep808 11:35 AM
firavia

1 
825 
Here is simple counter example to 2nd law of thermodynamics 
converting heat into work.
Everything is in vacuum,...

Sep808 09:19 AM
Constructe

12 
1,779 
In a 300kv electrical power line the electrons must be in a conduction band. How does that correlate with work...

Sep808 03:57 AM
carbrook

0 
1,360 
What is the classical microscopic mechanism for absorption of EM waves?
Consider a free charge isolated in the...

Sep708 08:38 PM
cesiumfrog

15 
2,036 
The D (displacement) vector has only the free charges as source.
I heard it is better to work with D than E, because...

Sep708 04:09 PM
Andy Resnick

12 
1,575 
1. When someone loops, and the person blocks, the ball goes out...if the ball really rides up the rubber, shouldn't it...

Sep708 07:39 AM
pingpongpaddy

10 
9,072 
hello smart people
I came across a weird equation for entropy and do not know how it was derived.
It looks like this...

Sep608 08:39 PM
Count Iblis

3 
5,352 
I have been learning the concepts of voltage, current, and resistance. I am aware of Ohm's law and have read a lot of...

Sep608 08:33 PM
russ_watters

25 
2,758 
Hi.
In electromagnetics, a material(linear,isotropic,homogenous) with constitutive parameters \epsilon and \mu has...

Sep608 06:38 PM
Antenna Guy

1 
5,269 
I just got an idea with believe that if an object of carefully choosen material is suspended in water(for now) and...

Sep608 11:29 AM
virtueboy15

2 
1,317 
in balancing masses , why do we always say that we need to put a mass in a rotating disk that produce a centrifugal...

Sep608 11:05 AM
firavia

10 
4,417 
A 2.41microF and a 7.38microF capacitor are connected in series across a 30.0V battery. A 10.3microF capacitor is...

Sep608 10:45 AM
rave7

1 
1,204 
I got a question that depicted the elliptical orbit of a comet over two intervals of the orbit, covering sectors, with...

Sep608 06:12 AM
tinytim

3 
2,730 
Is there a way to have some observables, apply an equation and find a measure if the system is chaotic or not?
For...

Sep608 03:06 AM
atyy

1 
1,070 
Hello everyone, I'm new to the forums, currently in grade 12. I'm planning to build a linear multistage coilgun as a...

Sep508 09:51 PM
Lancelot59

0 
1,198 
L = \frac{\partial \Phi}{\partial \left(cos \Theta \right) \ \partial \Omega}
What is this quantity? I mean, I...

Sep508 12:25 PM
Somefantastik

3 
1,702 
Hi,
In the process of reading up about dark energy in the field of cosmology, I felt I was beginning to lose sight of...

Sep508 10:30 AM
mysearch

1 
1,692 
Hello,
Here is my question:
Just imagine the sun would stop shining, without exploding. It would just totally...

Sep508 10:06 AM
h4tt3n

8 
31,307 
I have a question about waveguides:
Say your input is an electromagnetic field of a certain time frequency, energy...

Sep508 08:35 AM
fisico30

0 
948 
Hi, i would like to calculate a field after passing through a lens using fresnel integrals.

Sep508 04:48 AM
mdegama

0 
1,366 
what will happen if light passes through changing magnetic field?

Sep508 12:20 AM
atyy

13 
2,366 
My electrodynamics lecturer was talking about how potentials are arbitrary and that's why we have different gauges....

Sep408 02:02 PM
granpa

2 
1,398 