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

Apr2211 05:26 AM
ZapperZ

1 
48,278 
Hi guys,
I'm trying to implement the enthalpy equation in C++ converting it from an excel macro I found on this...

Sep1608 11:49 AM
Mike222

1 
1,725 
Hello,
I have to learn about the classic Perturbation Theory.
I'm looking for guides, text books etc about...

Sep1508 12:09 PM
Theherod

2 
1,120 
I know it when I see it but what is the exact definition of a wave? what makes a wave a wave?

Sep1408 09:04 PM
skydancer46

18 
3,275 
I'm just learning about linear momentum in classical mechanics and I have a question about it. I'm not sure I...

Sep1408 12:56 PM
fluidistic

2 
985 
Hello people,
In an AC circuit, how is RMS current and Mean current defined as?
What is the practical meaning of...

Sep1408 03:28 AM
Andrusko

1 
1,348 
Would it be possible for a symmetric axial vector torque to be equivalent to the shear stress of two uniform...

Sep1308 05:07 PM
tinytim

1 
2,511 
Does anyone have the following book:
"Problem Solving in Electromagnetics, Microwave Circuit, and Antenna Design...

Sep1308 02:35 PM
fisico30

0 
1,008 
If two dielectric materials with dielectric constants k1 and k2 and thickness d1 and d2 are within two copper plates,...

Sep1308 12:58 AM
atyy

6 
2,454 
Anyone can tell me why there is a ve for the z= r cot theta for the picture shown below? thanks!
...

Sep1208 11:36 PM
Defennder

1 
3,366 
Wind turbines / hydroelectric turbines  I think the same fundamental Physics applies to my question. The fluid...

Sep1208 06:25 PM
rcgldr

9 
2,864 
hi!
I have a question regarding work done lifting an object vertically upwards, under water.
I am aware that work...

Sep1208 06:02 PM
Andy Resnick

7 
3,499 
I guess this question is very easy, but after it occurred to me, it has been torturing me for quite a while.
I...

Sep1208 11:43 AM
tinytim

6 
2,002 
May I know what does polarization direction for linearly polarized plane waves mean?
In general, does the...

Sep1108 10:33 PM
felicity87

2 
1,975 
Hi
Suppose there is a system of N particles and a total energy of E.
Now given energy eigenvalues of ε(n) = nhv ...

Sep1108 10:10 PM
qbslug

0 
1,237 
I was wondering why manufacturers only makes these antitheft systems send out a frequency of 58 kHz. Is there...

Sep1108 03:12 PM
Zilfarion

2 
1,195 
what is the effect of a magnetic field on a electron?
please with equations

Sep1108 01:47 PM
Doc Al

1 
693 
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 
1,080 
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 
2,239 
In one dimentional cases, will the velocity of a particle tend to the terminal velocity unregardless of any...

Sep1108 02:12 AM
Lucien1011

2 
1,331 
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 
2,410 
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 
1,519 
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 
19,971 
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 
2,300 
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 
2,275 
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 
2,043 
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 
676 
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 
6,175 
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 
3,278 
The relation between the angles for which the minima occurs for a Fraunhofer diffraction(parallel rays, large...

Sep908 07:15 AM
Antenna Guy

8 
1,916 
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 
5,069 
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 
1,981 
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 
547 
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 
1,208 
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 
3,061 
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 
827 
Here is simple counter example to 2nd law of thermodynamics 
converting heat into work.
Everything is in vacuum,...

Sep808 09:19 AM
Constructe

12 
1,793 
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 
1,365 
What is the classical microscopic mechanism for absorption of EM waves?
Consider a free charge isolated in the...

Sep708 08:38 PM
cesiumfrog

15 
2,064 
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 
1,602 
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 
9,141 