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

Apr2211 05:26 AM
ZapperZ

1 
45,347 
I was told that you need a low voltage, high amperage taser to make any damage. I know that touching devices with high...

Aug1909 02:44 PM
John Creighto

6 
21,786 
ive been trying to do this question all summer to no joy. ive got a flywheel in motion which then has a torque...

Aug1909 06:41 AM
tomhitchmough

2 
1,214 
Quantities, like photons, alpha/beta particles, can travel with a billiard ball like behavior. There are two...

Aug1909 03:22 AM
John Creighto

0 
591 
we've been studying te physics involved in bungee jumping. We went to a bungee site, and recorded data, such as length...

Aug1909 02:32 AM
glugger

10 
2,090 
1)What is the formal definition of a point charge? It is known, that coulomb's law , is valid for point charges? But...

Aug1909 02:08 AM
manofphysics

4 
1,631 
Hi ive been having an argument with a few friends about a theory of mine (based on what i can remember from my physics...

Aug1809 11:34 PM
sylas

16 
5,099 
I'm confused by coarse and fine grained entropy and how they're related to the standard Boltzmann and Gibbs equations....

Aug1809 10:18 PM
SW VandeCarr

1 
2,007 
This is a physics and math problem
The representation of a vector as a straight ray is problematic
Imagine an arc of...

Aug1809 03:07 PM
vin300

1 
522 
I recently watched the Feynman Messenger Lectures on project tuva. I hope some of you have watched the second video...

Aug1809 11:27 AM
Pinu7

4 
1,533 
Dear all,
I've found in many books forces acting between 2 parallel wires, but not between a magnetic field and a...

Aug1809 02:06 AM
fatra2

4 
653 
Let's say there is flat floor at y=0 . There is a rectangle of which two vertices are at (0,0) and (w,h). There is a...

Aug1809 01:23 AM
tom_backton

4 
761 
Yesterday my friend asked me: what will happen if a force F with constant magnitude is applied to one end of a free...

Aug1709 11:24 PM
kof9595995

5 
815 
I'm have some conceptual problems with electric fields and waves. When I think of electromagnetic waves I imagine...

Aug1709 10:39 PM
Born2bwire

7 
1,475 
My question is a basic one so patience would be appreciated =)
Say we have a train moving at velocity "v"...

Aug1709 09:47 PM
DaleSpam

9 
890 
I was doing some rotation problems the other day out of my physics textbook when I realized that invariably all the...

Aug1709 05:45 PM
espen180

2 
919 
What is the force (horsepower) required turn a 750mm diameter shaft with a mass of 1,000kg, at a velocity of 160 rpms,...

Aug1709 04:50 PM
Naty1

2 
842 
Hello all!
I just finished the following problem:
Consider a thin semiinfinite plate of negligible thickness...

Aug1709 03:32 PM
ZombieCat

2 
3,530 
hi all
I am trying to use a circuit of NiCr wire to heat a surface. I have setup my circuit using parallel...

Aug1709 02:13 PM
mgb_phys

1 
555 
I ran across this question on another site but I didn't understand the answer that was given.
The question asked...

Aug1709 01:08 PM
DaleSpam

21 
2,959 
Hello everybody!
I would like to know if the back pressure in a piezoelectrically actuated displacement pump with...

Aug1709 03:02 AM
frenchero

0 
986 
It seems like a simple question, but I get the feeling that there is a catch: You are standing on a plate attached to...

Aug1609 11:46 PM
russ_watters

46 
16,473 
I read the paper of Hehl and Obukhov (A gentle introduction to the foundations of classical electrodynamics: The...

Aug1609 01:29 PM
Ben Niehoff

2 
912 
A train is moving towards north at one place.
it turns towards north east.
here we observe that the radius of...

Aug1609 12:13 PM
lstellyl

1 
693 
Hi, I have a couple of questions here:
1st, I never really understood how magnetism induces current, like how does...

Aug1609 01:25 AM
bjacoby

12 
4,285 
Would it be possible to calculate the time it would take for heat to reach a given temperature between two rubbing...

Aug1509 06:47 PM
Q_Goest

5 
2,959 
friends,
in lightining conductor, a metal plate with number of spikes is connected to the top end of the conductor...

Aug1509 06:06 PM
tinytim

1 
641 
This is a somewhat unusual question.
I am looking for any physics problem
in which the number or factor...

Aug1509 11:39 AM
Mapes

10 
1,755 
Hello everyone,
I just joined the forum because my friends and I have been having an argument for a couple hours...

Aug1509 06:48 AM
kuruman

5 
747 
I know that this site is not for speculation, but can someone help me in this doubt ?:rolleyes:
I know that...

Aug1409 04:51 PM
StephenWeinst

16 
4,686 
Can someone explain magnets at the subatomic level to me? According to wikipedia, many of the electrons' spins are...

Aug1409 04:16 PM
kashiark

3 
1,151 
Is there a consensus on whether or not a coaccelerated observer measures radiation from an accelerated charge?

Aug1409 02:53 AM
vin300

19 
2,202 
folks,
in my attached image, why can't i take the vector ds as indicated by me in pencil. i am confused. help will...

Aug1309 11:27 PM
logearav

4 
937 
How do we apply Wilson eq. to find the activity coefficient.
Liquidphase properties and their correlation, dose it...

Aug1309 10:24 PM
kritbordin

0 
5,176 
I'm curious to know how the engineers of NASA determine how to join two moving, or orbiting objects in space. What...

Aug1309 09:22 PM
mikelepore

10 
1,013 
My doubt is that when we charge a battery we say that energy is transferred into it , but does the emf of a battery...

Aug1309 08:21 PM
Redbelly98

6 
2,842 
Hi All,
I'm familiar with this analogy:
"The voltage is equivalent to the water pressure, the current is...

Aug1309 03:58 PM
A.T.

16 
3,279 
In Feynman's lecture on the principle of least action, he show that you can describe electrostatics by saying that a...

Aug1309 12:35 PM
nassboy

0 
656 
\sum^{3N}_{i=1}\frac{p^2_i}{2m}\leq E
Why I can write this inequality? Is this E energy of system?

Aug1309 09:28 AM
Feldoh

3 
560 
I've just got some small problems this time.
The first being,do the particles at the axis of a rotating body really...

Aug1309 03:00 AM
BobbyBear

115 
8,748 
I myself am the artistic type, and was unsure where to look for help, so I'm posting here.
I'm trying to build a...

Aug1209 08:42 PM
Nick Walters

22 
2,245 