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

Apr2211 05:26 AM
ZapperZ

1 
46,985 
I just need some clarification.
In a lab that i did, a metal ball goes down a slanted ramp, onto a horizontal ramp...

Mar412 04:20 PM
uknew

14 
1,949 
Is the phase diagram for an oscilliator (all sorts of oscilliations) always clockwise? If it is so, why?

Mar412 06:04 PM
Redbelly98

2 
1,063 
Is there a formula/equation that proves the Zeroth law, that can be confirmed by experiments?
And another quick...

Mar512 12:11 AM
lugita15

20 
3,881 
If a mass was hanging vertically from a spring under its own weight.
In the static equilibrium position, using up...

Mar512 03:42 AM
tinytim

1 
1,126 
the radii of the curvature of the spherical surfaces which is a lens of required focal length are not same. it forms...

Mar512 06:25 AM
komal bisht

2 
1,044 
Often a time varying Efield is represented in complex format. I have a simple Efield (uniform in space) given by
...

Mar512 09:28 AM
chrisbaird

2 
806 
If a small tube (capillary tube) is dipped into the water, the water level rises. Which means someone is doing work on...

Mar512 09:41 AM
chrisbaird

3 
785 
Confused.. please help!
Often when an electric field varies sinusoidally with time, it is represented as a complex...

Mar512 11:07 AM
chrisbaird

6 
2,293 
I'm kind of struggling with the concept of energy. A particle in a conservative field has kinetic and potential energy...

Mar512 11:08 AM
A.T.

3 
1,409 
Hello forum,
I have a question about photonic crystals.
From Wikipedia: "photons (behaving as waves) propagate...

Mar512 11:40 AM
chrisbaird

2 
1,022 
Hi
Consider the case of a charge placed inside the cavity in a metal. Let the charge be at A. Assume that the...

Mar512 11:55 AM
Hassan2

5 
1,010 
Hi,
An object is falling near the surface of the Earth. We assume there is a drag force acting on it due to the air...

Mar512 02:15 PM
skazis

3 
1,144 
If I have a fuse with a rating if 5A and when I connect 10 bulbs in parallel, the current flowing will be 5A. When...

Mar512 05:44 PM
Redbelly98

7 
1,465 
I have come across books titled "engineering electromagnetics" and "electromagnetics with applications" but I could...

Mar512 06:56 PM
Drakkith

6 
2,202 
Hello, My question is simple, please look at the attached images and explain why the geometrical interpretation for...

Mar512 07:12 PM
BugBear

0 
1,060 
I know those nice pictures showing light polarization, but the light wave should be three dimensional, so no up and...

Mar512 08:41 PM
Drakkith

12 
1,613 
This is probably a trivial problem, but I can't get it straight. It's well known and easy enough to show...

Mar512 10:25 PM
apb000

6 
1,293 
This is probably a stupid question with a simple answer, but please bear with me.
Suppose we have a bucket of water...

Mar512 11:12 PM
dEdt

2 
598 
I'm aware of the equation
ΔU = Q + W
ΔU is the change in internal energy which equals 3/2 nRΔT
Q is heat transfer...

Mar612 12:10 AM
wongrufus

2 
1,256 
Is impulse only really used in real life because of the instruments you might have? I'm having trouble understanding...

Mar612 02:39 AM
Philip Wood

4 
1,233 
This is not a HW question!!! THIS IS A DISCOVERY that I want to explore. I will explain it as follows:
Suppose I...

Mar612 06:47 AM
Femme_physics

5 
856 
I'm getting confused with the problems that ask you to find potential and when to use the rule that the sum of all the...

Mar612 06:48 AM
pabloenigma

1 
1,237 
I'm not sure where to post this question. In classical mechanics many problems are simplified in the approximation of...

Mar612 11:22 AM
fluidistic

4 
1,234 
Eisberg and Resnick says that the condition for stability of the atom is:
k Ze2/r2=mv2/r
What I fail to...

Mar612 03:34 PM
Philip Wood

1 
930 
I am teaching mechanical energy, that is, gravitational potential and kinetic energy, to middle schoolers.
Of...

Mar612 04:32 PM
genericusrnme

12 
1,529 
When deriving the workpotential energy theorem, my book states that dV (derivative of the potential energy) is equal...

Mar612 09:06 PM
pabloenigma

1 
822 
I have discovered something that will change the way we heat our homes and water. Gas and Oil Furnaces / Hot Water...

Mar612 09:23 PM
DaveC426913

7 
1,640 
My text was able to show that for an ideal (incompressible and inviscid) and steady fluid in a gravitational field,...

Mar712 04:16 AM
Jano L.

7 
837 
I have a pedagogical question, and a philosophical question, both involving energy:
1) All the derivations...

Mar712 07:16 AM
Riad

59 
7,560 
I am asked by my student this seemingly easy question.
I searched on the net on got two answers.
1) tension is the...

Mar712 08:51 AM
Andrew Mason

4 
1,467 
I'm currently taking Calculusbased Physics II, an introductory to electromagnetism. While I'm working hard to...

Mar712 09:45 AM
NanoPassion

6 
1,452 
In my book it says: The bigger entropy of a system, the more heat from the surroundings can enter it. Now, I don't...

Mar712 02:22 PM
aaaa202

2 
773 
I'm not asking why the electron doesn't fall into the nucleus. I know this is explained by quantum mechanics.
But...

Mar712 05:52 PM
LogicX

2 
936 
Hi all,
Here is what I am trying to understand qualitatively. It is NOT a homework problem:
A long,...

Mar712 10:14 PM
DaveC426913

1 
668 
It’s very well know that Maxwell equations bring the solution for plane waves but as far as I know I cannot use them...

Mar712 11:29 PM
SergioPL

4 
892 
I've noticed in several of my problems involving conservation of momentum, that the rotational kinetic energy of a...

Mar812 01:31 AM
willem2

1 
1,111 
A voltmeter must always be connected in parallel right? But when I have a transformer's secondary coil which is...

Mar812 02:01 AM
sgstudent

0 
881 
My textbook (Halliday & Walker) explains that a charged conductor (a solid, of an arbitrary shape) in electrostatic...

Mar812 04:53 AM
Hassan2

17 
2,621 
Suppose we have a spring placed vertically on a table. We put a body with mass "m" on it. The spring compresses by...

Mar812 08:39 AM
superalias

6 
1,638 
Does anyone know when is the Potential explicitly timedependent? Can you give me an example?

Mar812 10:37 AM
Hassan2

1 
872 