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Again, for some odd reason, people...

Apr2211 05:26 AM
ZapperZ

1 
46,937 
Hello,
I've been going through some cavity material and attempted analyses regarding transverse modes.
...

Aug913 04:25 PM
hangainlover

0 
355 
Folks  doing some research and just needed a reality check on acceleration  let me know if this makes sense:
If I...

Aug913 12:30 PM
jbriggs444

1 
365 
In page 555, Appendix B of Intro to electrodynamics by D Griffiths:
\nabla\cdot\vec F=D,\;\nabla\times\vec F=\vec...

Aug913 12:06 PM
yungman

0 
374 
i understand why there can be no breakdown, however "arcing" is just the transfer of electrons. a breakdown in air...

Aug913 11:06 AM
ZapperZ

13 
1,315 
The unit consists of a single, long rectangular chamber. On the inside is a moving wall. On one side of the wall is a...

Aug913 06:40 AM
russ_watters

6 
481 
Hello, I was thinking about induced currents in a wire(coil). For example when a current from an external source...

Aug813 07:37 PM
ataskaita

3 
571 
Hi guys,
I've been struggling with this concept for a few days now.
I have this *good* image that I am blurring...

Aug813 06:25 PM
Drakkith

1 
445 
This is question 2.30 from the 2nd edition of the Purcell book on Electricity and Magnetism. It's an interesting...

Aug813 02:55 PM
WannabeNewton

6 
696 
I have a basic understanding of electrostatics but can't quite get my head around how a Faraday cage works. If you...

Aug813 12:26 PM
sophiecentaur

3 
465 
I have little confusion about understanding a lecture note for calculation of work done by a expansion of gas.
...

Aug813 08:16 AM
Doc Al

1 
410 
I'm a bit confused with the equation for a long solenoid. The usual derivation has us consider a rectangular loop...

Aug813 06:24 AM
OperationalAmp

1 
470 
This is an attempt by a novice to do something neat. Please feel free to correct me.
I am trying to see if one can...

Aug813 05:34 AM
crastinus

2 
746 
I was reviewing some things relating to electric fields around conducting surfaces, and the book I was using (Purcell)...

Aug813 04:48 AM
gadong

3 
389 
a man moves in an open field such that after moving 10 m on a straight line he makes a sharp turn of 60 degree to his...

Aug713 11:45 PM
jtbell

2 
649 
can selfinductance and kinetic inductance be combined in the same model?

Aug713 08:54 PM
dirad

2 
326 
k being the one from the harmonic wave ψ(x,t) = Asin(kx  ωt) where k = 2π/λ
The way I see it right now, k is just...

Aug713 04:52 PM
lightarrow

4 
691 
All bodies with a temperature emit electromagnetic radiation also known as thermal radiation or blackbody radiation. ...

Aug713 12:08 PM
Naty1

3 
488 
Hi all,
This is probably a silly questions, but I want to be sure :).
I'm wondering if a real image, created by...

Aug713 07:41 AM
Philip Wood

15 
1,030 
My question is in Griffiths Introduction to Electrodynamics 3rd edition p48. It said
Two expressions involving...

Aug613 09:33 PM
king vitamin

7 
732 
Hi,
I work in the construction industry. I have a homeowner that would like to protect herself from electromagentic...

Aug613 07:05 PM
SteamKing

7 
630 
Hi,
I'm interested in reflection of both particles and light off surfaces. My problem is associated with a model...

Aug613 05:40 PM
HP123

2 
473 
According to the third law of thermodynamics, one could argue that a vacuum has zero entropy, since it has only one...

Aug613 12:48 PM
Maximise24

25 
1,688 
Hi,
I know that for a massless spring the tension is T = kx, where k is a constant and x is the compression or...

Aug613 10:51 AM
AlephZero

7 
805 
Why dose v = d/t ?

Aug613 09:14 AM
usernameee

6 
595 
I am looking for an exact value of absorption coefficient of aluminium for microwaves, but I can not find it in the...

Aug613 08:01 AM
johnbbahm

3 
495 
I've been trying to obtain an equation of position in terms of time given force in terms of position. I've tried and I...

Aug613 04:38 AM
WannabeNewton

9 
572 
I am studying Coulomb and Lorentz gauge. Lorentz gauge help produce wave equation:
\nabla^2...

Aug613 03:07 AM
WannabeNewton

3 
443 
If you know how much heat a bar is putting out, what is the temperature at the center of the bar?

Aug513 06:08 PM
CWatters

2 
693 
Trying to get my head around constructive/destructive interference in thin film optics. The book does a good job of...

Aug513 01:39 PM
Gauss M.D.

2 
551 
First of all, I want to say that I am totally ignorant about physics. And I do not understand the general concepts of...

Aug513 09:33 AM
tarekatpf

49 
2,809 
Say you have a rope looped around a frictionless pulley, and a mass m is attached to each side of the rope. When the...

Aug513 09:14 AM
lightarrow

16 
1,064 
I am trying to write a program to show the flight of a satellite in the neighbourhood of two large planets. In all of...

Aug513 07:24 AM
Rapidrain

8 
482 
I'm researching dark matter and how it affects galaxy rotation curves, I came up with the problem below.
Imagine a...

Aug513 06:18 AM
tade

2 
293 
See attached scanned pages of page 118(left side) and page 125(right side) of Antenna Theory by Balanis.
On the...

Aug513 04:02 AM
andrien

26 
1,294 
I understand ##\vec A\rightarrow\vec A+\nabla \psi\;## as ##\;\nabla \times \nabla...

Aug513 03:58 AM
vanhees71

9 
522 
I have these two problems on energy where I just don't totally understand the explanations given. One goes:
(With a...

Aug513 01:52 AM
technician

3 
470 
i haven't been able to obtain a simple answer

Aug413 10:00 PM
yungman

6 
1,251 
If I throw a ball vertically upwards from the surface of the earth, the upward motion slows due to gravity. At the...

Aug413 09:17 PM
DaleSpam

27 
1,191 
Hi
I'm trying to get my head round why Maxwell's equations fail for the electron going round the atom.
The...

Aug413 03:27 PM
WannabeNewton

2 
390 
Is there a way to calculate angular acceleration from the change in angular velocity and the change in the angle...

Aug413 01:23 PM
WannabeNewton

8 
547 