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Again, for some odd reason, people...

Apr2211 05:26 AM
ZapperZ

1 
48,243 
Hey, I'm doing a research on artificial satellites, and I'm really confused about the escape velocity required for an...

Sep1314 12:04 AM
Murtuza Tipu

12 
355 
http://www.youtube.com/watch?v=ltnLOkaCBo
I have been using this skill for a few months now and I feel like it is...

Sep1214 08:59 PM
bothan

10 
444 
So I understand that a black body is a diffuse emitter, and that it radiates energy at a rate of σT^4.
I also...

Sep1214 07:44 PM
elegysix

1 
220 
Hi PF community! I'm currently doing a research paper on artificial satellites, and I've made a list of things that...

Sep1214 06:48 PM
Crutchlow13

6 
217 
During summer my swimming pool is 23° C and my loft air is 53° C. (73° F / 127° F)
The sun shines on the metal...

Sep1214 06:02 PM
Sten Larsen

24 
674 
Case 1. You have a sphere with Radius R and middle point X with the charge Q. The charge is equally distributed over...

Sep1214 09:48 AM
vanhees71

1 
158 
I'm taking E & M II... Would anyone agree that the following statements are true?
An electric field changing in...

Sep1214 06:47 AM
Shyan

5 
209 
Okay guys, I still feel like I don't quite understand these concepts well enough. Do you guys have any websites or...

Sep1214 02:33 AM
Nugatory

1 
186 
Hi!
I try to get some intuitive understanding on the equipartition theorem stating that in thermal equilibrium,...

Sep1214 01:55 AM
center o bass

2 
205 
If fan blades move in a circular way how is the air moving towards you (in front of fan) ?
Also propeller and fan...

Sep1214 01:52 AM
A.T.

5 
211 
In the attached figure, a deenergizing RL circuit is drawn (left switch is opened while right switch is closed). In...

Sep1114 07:44 PM
gsal

1 
183 
Hello everyone.
I've been struggling with how to deal or solve questions that include variable masses. Considering...

Sep1114 04:59 PM
Nugatory

6 
216 
I'm wondering if someone is observing a situation from a frame moving in a uniform circular motion, would that frame...

Sep1114 09:09 AM
Nugatory

8 
366 
Hi,
The permanent gases like Nitrogen, Helium etc. have more specific heat capacity as liquid than their gases....

Sep1114 05:44 AM
AbhiNature

0 
153 
I'm looking for a "simple" calculator, most likely a matrix based thing, to allow me to work out the size of an image...

Sep1014 06:47 PM
Andy Resnick

1 
137 
I do not really understand the big picture of gauss law. For what I know a conductor is a material where electrons can...

Sep1014 05:38 PM
TrueColor

2 
251 
Trying to get my head around some ideas about "rechargeable" batteries and getting in a muddle!
So I get the idea...

Sep1014 02:50 PM
DeltaČ

4 
189 
There is a conducting circular loop with resistance R falling in the magnetic field ...

Sep1014 10:43 AM
Shyan

4 
310 
Imagine an electromagnet with two pole faces, one flat (N) and one pointed (S). If you put a diamagnet in between...

Sep914 09:33 PM
Meir Achuz

7 
251 
Is it possible to generate energy from the earth's rotation? Imagine a Foucault Pendulum attached to a dynamo shaft?
...

Sep914 06:23 PM
jbriggs444

46 
1,284 
I am trying to derive part of the navierstokes equations. Consider the following link:
...

Sep914 06:16 PM
DeltaČ

4 
213 
Hello
Is there any way that RH over water in a closed container coud not be 100%? Assuming that the walls of the...

Sep914 04:08 PM
Roger44

7 
229 
Say I drop a ball of mass 5kg from a height of 2 meters, assuming no air resistance, it will hit the ground with a...

Sep914 10:58 AM
pyman12

5 
193 
Imagine a beam of light diverging from a source and being incident on a detector. Now imagine a similar set up but...

Sep914 07:35 AM
Dadface

7 
278 
The classical approximated formula describing frictional force is f = N\mu, directed oppositely to the motion...

Sep914 04:54 AM
A.T.

4 
187 
Derivation of Helmholtz's energy is
$$dF=pdvSdT$$
Derivative of Gibbs's energy is
$$dG=VdpSdT$$
In the...

Sep914 02:00 AM
sweet springs

0 
185 
Suppose we refine some of terms in thermodynamics based on the follow statements:
1. All energy has two components:...

Sep814 02:46 PM
DaleSpam

2 
204 
Hello all. I have been searching for information on wave beats in light but haven't been very succesful. I have found...

Sep814 12:41 PM
olivermsun

8 
322 
Frictional force opposes relative motion and not just motion. Can you please give an example to further explain this...

Sep814 07:02 AM
Philip Wood

5 
243 
http://i.imgur.com/GP6QorG.jpg
I don't follow the integration in it.
I'm assuming Fx(x,0) and Fy(1,y) are the...

Sep814 12:13 AM
DeltaČ

1 
184 
According to my book, and wiki...

Sep714 04:00 PM
Nikitin

6 
286 
the question is that there is a particle in 3 spatial Euclidean dimensions in cylindrical coordinates.
I want to...

Sep714 12:59 PM
noor

2 
144 
I am trying to calculate heat transfer from an inclined flat plate under free convection conditions. I am referring to...

Sep714 12:49 PM
Libertiene

7 
303 
Suppose we apply a uniform field to an infinite conducting slab (i.e. like an infinite parallel plate capacitor, but...

Sep614 07:58 PM
Nugatory

2 
231 
Hi, I'm new here, I was just wondering if anyone could help clarify a subject I'm having difficulties teaching...

Sep614 07:23 PM
Simon Bridge

1 
178 
Hello,
I have a conducting copper ring of inner radius a and outer radius b.
point charges Q pass through the centre...

Sep614 04:23 PM
Philip Wood

3 
320 
Hi All,
This is from a classical mechanics problem, and I already 'solved' the problem, but I'm interested in why a...

Sep614 04:18 PM
voko

3 
163 
The circular loop carrying current experience a tension in external magnetic field.how can this tension be calculated...

Sep614 04:00 PM
Meir Achuz

1 
140 
Suppose I have a cubic lattice of N^3 masses, M, each connected to six nearest neighbors with springs of constant k...

Sep614 02:22 PM
Spinnor

1 
175 
I have learnt in 1st year that the underdamped simple harmonic motion can be described by the differential equation ...

Sep614 09:34 AM
Philip Wood

5 
303 