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

Apr2211 05:26 AM
ZapperZ

1 
47,787 
"Setting Your Thermostat for Maximum Energy Savings" by Jeffrey Orloff claims that during warm months, setting an air...

Apr2612 03:20 PM
QuantumPion

13 
3,678 
Can anyone tell me the value of cyclotron frequency with full mathematical proof and explanation?

Apr2612 01:49 PM
Bob S

2 
629 
For a wave travelling from a medium with refractive index n1 to n2 with n2 > n1, the amplitude reflection coefficient...

Apr2612 12:00 PM
Born2bwire

1 
2,725 
In Feynman lectures vol 2, chap 28, it is given that for an electron at rest, the net self force exerted on itself is...

Apr2612 08:49 AM
Dickfore

13 
1,666 
There are (at least) two issues regarding the presence of ferromagnetic materials around an MRI scanner (of strength...

Apr2612 07:54 AM
dhigger

0 
816 
I am doing a presentation on energy as part of a class project.As part of the presentation I would like to physically...

Apr2612 05:50 AM
Philip Wood

3 
907 
Hi,
In class we were discussing the effects of a two bar magnets being dropped through a copper tube at around the...

Apr2612 03:43 AM
Xiao10

2 
1,297 
I have a quick question about the retarded time when dealing with moving charges.
The retarded time is:
t' = t...

Apr2612 01:05 AM
K^2

1 
1,152 
I'm working with a 3000 RPM @ 0.85 Nm motor in the transaxle from a powered scooter (like for disabled/elderly...

Apr2512 11:57 PM
magnethead494

14 
1,828 
I was thinking about how planets revolve around sun. Although they subscribe a elliptical motion, my question is very...

Apr2512 09:31 PM
nikeadidas

2 
654 
Carnot engine efficiency is:
\eta_{work} = 1  \frac{T_c}{T_h}
Carnot refrigeration efficiency is:
\eta_{cool} =...

Apr2512 05:24 PM
russ_watters

2 
3,899 
The kinetic theory of gas state that p=(1/3)(N)(m)(u^2)/(V).
In one step of its derivative related to change of...

Apr2512 04:35 PM
haruspex

3 
970 
How we differentiate the amount of Energy of a bullet fired by a gun and a rifle with same linear velocity?
do...

Apr2512 04:08 PM
tinytim

2 
842 
I had my physics midterm today and I totally blanked out. I want to know how to solve it for next time.
So In the...

Apr2512 03:33 PM
tinytim

1 
943 
Hello
I'm tasked to evaluate the roof of a small power station situated beneath a rather high tower in an alpine...

Apr2512 02:52 PM
Microcephalus

3 
1,593 
Hello,
When looking at Mohr's circle, why is σ_x 180 degreees away from σ_y
I thought forces in orthagonal...

Apr2512 12:12 PM
terryphi

0 
647 
Hi,
I was curious if you could help me. I am currently working on a project where we are using 12g CO2 cylinders to...

Apr2512 11:56 AM
IPFWengineer

0 
694 
The continuous version of the Lorentz force is
\mathbf{f}=\rho\mathbf{E}+\mathbf{j}\times\mathbf{B}
but what...

Apr2512 10:56 AM
pellman

0 
672 
i'm in my freshman year and i'm starting to learn Derivatives in Calculus, and I was wondering, once Ek (kinectic...

Apr2512 10:40 AM
yoelhalb

2 
875 
In Reif's book Fundamentals of Statistical and Thermal Physics, he labels two formulas as the StefanBoltzmann Law. ...

Apr2512 08:39 AM
PatF

2 
1,044 
Does anyone know of any simple aerodynamics simulators? Preferably one that would allow me to import a 3D model and...

Apr2512 07:40 AM
rod tanis

5 
14,590 
Hi guys, I have a dyanamics question to ask. Thanks for the help!
In the scenario there is two objectsone the box...

Apr2512 02:23 AM
sgstudent

3 
1,615 
In viewing a derivation of the formula describing the intensity of the interfering waves, I noticed how the electric...

Apr2512 02:04 AM
Sefrez

2 
1,576 
Hi,
I have some questions regarding on the locating of the center of gravity. I have read some txtbk regarding on...

Apr2412 09:16 PM
siukwok

5 
3,218 
Say we have a gearing system of the ratio 4:1 is the acceleration of the smaller gear 4 times greater than the...

Apr2412 09:03 PM
OldEngr63

2 
951 
I need dipole moment of anisotropic dielectric sphere
The dielectric tensor is given in cartesian matrix
I try to...

Apr2412 08:37 PM
david12345678

0 
827 
We know that work is the dot product between force and displacement .. so dot product always gives scalar (horizontal...

Apr2412 06:29 PM
kmarinas86

10 
5,448 
Let's say there are two rigid bodies in space, each has an initial translational velocity as well as an initial...

Apr2412 05:48 PM
haruspex

4 
1,104 
I'm going through the Light & Optics chapter of Kaplan MCAT prep material & am having a hard time conceptually...

Apr2412 08:32 AM
grindfreak

1 
6,191 
Hello,
Im new here and I hope someone of you can answer this probably trivial question. I tried to find the answer...

Apr2412 06:33 AM
haruspex

2 
946 
I am doing a project, where I am measuring the tension exerted by different guitar strings from different sets for the...

Apr2412 06:14 AM
haruspex

1 
1,009 
Since I train powerlifting I have started to get interested in the mechanical analysis of the different exercises. But...

Apr2412 06:08 AM
abramroyy

6 
4,379 
So I read about a scientist who wrote a physics proof to prove that he did not run a stop sign, basing his argument on...

Apr2412 06:06 AM
Jasso

3 
1,426 
Hi everyone!
I've been learning about electric potential energy and electric potential and from what I've read, it...

Apr2412 05:48 AM
haruspex

2 
1,671 
Hello,
So presume we have a system in which a chemical process A + B > X + Y is happening. We allow it to be a...

Apr2412 01:34 AM
DrDu

3 
832 
I'm a little confused about the analysis of TM and TE modes.
As per definition, TE modes have only H (magnetic...

Apr2312 08:53 PM
Bob S

15 
10,288 
When looking for chaos in the n body problem what should i do?

Apr2312 10:13 AM
sambristol

1 
731 
The essence of Gauss' law is that the total flux through a closed surface only depends on the charge inside the...

Apr2312 08:16 AM
tinytim

8 
1,301 
Hi, why does the energy of the system equals the sum of the energy of the modes? The book I'm reading only states it,...

Apr2312 07:49 AM
AlephZero

3 
1,214 
I have an anaerobic digester with a volume of 2500 m^3 and internal temperature is 60°C. But, average outer...

Apr2212 11:06 PM
haruspex

5 
826 