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

Apr2211 05:26 AM
ZapperZ

1 
47,887 
If I have a heatsink which I know the natural convection thermal resistance (TR), is there a way to calculate or...

Apr1412 06:07 PM
JerryG

0 
1,517 
When there is a lamp on a wall and the light from the lamp falls on the wall, we notice that the shape formed by the...

Apr1412 05:17 PM
haruspex

3 
863 
Hi,
can anyone help me to understand why the pressure of a ideal solid is zero?. In my class we calculated this in...

Apr1412 03:17 PM
dapias09

0 
736 
I try to understand how gravity in 1/h² can compensated torque give from film of water between 2 helicoids. 2...

Apr1412 03:07 PM
Gh778

0 
698 
So I'm trying to analyze a scenario in which I have a plane wave incident (from, say, some medium with permittivity...

Apr1412 01:46 PM
VortexLattice

4 
974 
In the Lorenz gauge, the Maxwell equations reduce to four inhomogenous wave equations, with the charge density acting...

Apr1412 01:05 PM
jjustinn

8 
1,517 
There are many good treatments of the classical central force problem in many undergraduate and graduate text books. ...

Apr1412 12:45 PM
jjustinn

1 
882 
Some have said it was 6000 degrees K.
I'm not so sure.
I know for sure that you can increase solar intensity...

Apr1412 11:34 AM
DaleSpam

42 
3,861 
Why is it easier to push a load on a wooden crate on wheels when you are nearer the load and the lever is shorter and...

Apr1412 11:22 AM
DaveC426913

3 
816 
My research is related to magnetism and I'm supposed to have a good understanding of permeability but I'm afraid I...

Apr1412 10:04 AM
Hassan2

2 
2,028 
I was reading through my notes and this idea popped into my head:
If you had to drop a liter of water from a certain...

Apr1412 04:42 AM
Dadface

9 
985 
I've preformed an experiment about the speed of sound waves in water and I found that sound travelled faster in hot...

Apr1412 04:14 AM
Bobbywhy

1 
5,402 
Hello. I have a question about when the Lagrangian can be used. In the textbook we are using it is shown that for...

Apr1412 03:21 AM
dsdsuster

2 
969 
Hello, I'm having some issues with Love's equivalence principle.
I'm studying Balanis' "Antenna theory" (1997),...

Apr1312 04:32 PM
eliotsbowe

4 
1,822 
Hello,
I'm trying to create a model of pendulum motion in Matlab to fit the curve we measured in class, and it has...

Apr1312 03:37 PM
mathman

1 
1,823 
i know these topics are discussed many times and i have read many of them but still have a doubt.
Suppose a car is...

Apr1312 03:20 PM
Creator

3 
671 
Hi Guys,
Given a resistor, I understand how to use the bands to calculate the resistance, but how does one tell...

Apr1312 12:24 PM
Jasso

6 
1,044 
I learnt that solids conduct heat by vibrating and thus transferring the energy from one particle to another particle....

Apr1312 06:43 AM
sgstudent

7 
1,488 
The above equation gives the EPE of two point charges separated by a distance r.
Firstly, I do not understand how...

Apr1312 04:57 AM
elemis

10 
1,022 
Hi guys, I derived an equation for determining orbital period, given an altitude, speed, and mass of the primary and...

Apr1312 01:00 AM
Creator

7 
3,715 
It's just a simple question about the pressure under and over the plane's wing problem that I'm trying to answer....

Apr1212 09:05 PM
cjl

17 
2,581 
Why is it that only Canonical transformations preserve the Hamilton's equations? Or what makes noncanonical...

Apr1212 07:20 PM
Dougy81

1 
639 
Hi guys not sure if this belongs in the homework section, anyway here goes!
I'm trying to calculate the total...

Apr1212 06:13 PM
smalveh

4 
749 
For example the microcanonical ensemble uses a dirac delta distribution on a certain energy shell E, which is not...

Apr1212 04:01 PM
nonequilibrium

0 
705 
Hello,
I have this problem with deriving the formule from de definition of potential energy
Picture show a...

Apr1212 03:16 PM
HWGXX7

8 
1,368 
Mathematically,its easy to say that when the distance between the points tends to zero,for the dipole moment to stay...

Apr1212 11:30 AM
ashishsinghal

2 
1,409 
Imagine that I pour a bowl of water onto the stones in sauna. So, the problem is that I need to estimate how much did...

Apr1212 09:56 AM
Hg00000

3 
1,768 
What, other than recoil, the user's unsteady hands and gravity, causes bullets to impact different places on the...

Apr1212 08:17 AM
mfb

3 
817 
Hello, everyone.
I'm working on simulating shallow water flow. I'm using the MacCormack scheme and fractional...

Apr1212 07:45 AM
MartinV

1 
1,342 
If I push a cylinder along a surface with friction then am I right in saying that it would almost instantly start a...

Apr1212 05:19 AM
Filip Larsen

4 
1,163 
Hi,
I want to know if one sees a canonical transformation that would transform the following Hamiltonian in the...

Apr1112 11:57 PM
Dougy81

0 
1,072 
I'm at the end of my vector calculus textbook, and there is a section on how vector calculus can be used to derive...

Apr1112 11:25 PM
victor.raum

5 
991 
Suppose I have two metal spheres, radius 1 metre and 1 cm.
I charge the small one to 100V.
The selfcapacitance of...

Apr1112 08:58 PM
sambristol

1 
1,290 
Hi,
I'm having some trouble understanding how this works. I'm trying to put the pieces together but I'm hoping...

Apr1112 08:49 PM
mindoftea

7 
1,886 
Hi,
I am trying find equations for continuous "stretchy" collisions, in other words, I have two perfectly round...

Apr1112 06:54 PM
mindoftea

3 
1,195 
Hey there, I've been reading a lot about piezoelectric materials lately and I've steel looking for an answer for a...

Apr1112 03:55 PM
itamar

0 
830 
Hi,
I was studying Cherenkov radiation and here's what I read. A charged particle moving through a medium has an...

Apr1112 03:46 PM
McLaren Rulez

3 
796 
I would like to calculate the torque on the air object under water. The pressure is only give from water (water...

Apr1112 11:46 AM
Gh778

5 
1,008 
I always hear a difference between transverse and longitudinal waves, and, standing and traveling waves, but for me,...

Apr1112 07:50 AM
Doc Al

6 
10,471 
A cable weighing 10kg/m supports a 250kg beam(AC) hinged at the wall(BC). The beam is 4.5m long.
Find the length of...

Apr1112 05:51 AM
jayman16

0 
1,147 