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

Apr2211 05:26 AM
ZapperZ

1 
48,261 
Hello everybody,
i wanted to ask what changes when i unite two magnets ??
except from the dimensions does...

May1313 07:06 AM
Simon Bridge

3 
355 
In a freefall problem, 9.8 m/s^2 works fine as long as you stay close to the earth. However, if you are falling from...

May1213 10:43 PM
Simon Bridge

1 
571 
why is it when you stack two blocks on each other that the top box with mass M_t has a normal force of M_t and a...

May1113 03:56 PM
joshmccraney

4 
590 
I was reading Feynman's Lecture on Physics, chapter 28, where he mentioned the formula for the electric field...

May1213 03:23 PM
yjoe61

2 
313 
I understand how to work with vectors but I am not yet very confident on how they work or think about them. I am...

May1213 05:51 PM
Googl

10 
613 
when we need to find the direction of radial velocity should we move our right hand from the omega (angular frequency)...

May1313 08:49 AM
rohit199622

4 
603 
Hi,
I understand that some physical quantities in electromagnetism are analogous to physical quantities in heat...

May1213 04:35 PM
technician

4 
774 
Second law of thermodynamics states that heat does not flow spontaneously from cold to hot bodies. But a cool...

May1413 10:58 AM
Andrew Mason

8 
978 
Is it true that all thermostatics and thermodynamics can be deduced from the supossition that entropy S for all...

May1213 05:09 AM
StarsRuler

0 
311 
I have built a new electromagnet, my second one so far, in an attempt to make it better. I am trying to find its...

May1313 06:59 AM
Pharrahnox

4 
501 
I am study chapter 5 of An Introduction to Thermal Physics by Schroeder and I am having trouble understanding his...

May1213 03:35 AM
vanhees71

1 
3,102 
Hi,
I have a generic question about solving kinematic problems using simple calculus. For eg.
A variable force...

May1213 03:45 PM
voko

3 
854 
I'm confused about the condition for spontaneity for the Helmholtz energy. My textbook (McQuarrie, "Physical...

May1113 11:02 PM
Jano L.

11 
563 
We all know that there is a force between them. But I wonder... if electrons in both wires are moving with the same...

May1213 01:40 PM
Introyble

3 
432 
Hi all,
I want to use SPH discretization for my cooling rate but i don't know if its valid.
So, this is the...

May1413 08:57 AM
ronin777

0 
343 
Does the electric polarization density of a dielectric inside a capacitor have the same direction as the electrical...

May1113 09:23 AM
vanhees71

1 
402 
Hi all
I have a situation where i have a molten Aluminium Copper alloy melt poured in a mould
to be solidified....

May1413 02:43 PM
ronin777

2 
468 
0k i know net force on a body is defined as mass times acceleration of the body w.r.t inertial frame,
but how do we...

May1213 02:45 AM
tinytim

8 
611 
big G = G = 6.674E11 N(m/Kg)^2
Mass of earth = Me = 5.972E24 Kg
Radius of earth = Rsurface = Rs = 6.371E6...

May1213 04:51 AM
cawthorne

4 
664 
In the mathematics of Calculus, a basic requirement is that the system or function should be continuous. Until the...

May1413 10:19 AM
SteamKing

3 
380 
Hi,
Recently I came across an annular permanent magnet (round magnet with a hole in it) which had fallen and broken...

May1213 05:33 AM
CompuChip

6 
842 
Coriolis effect  In a nonfriction system, f I roll something along the surface of the planet from on of the poles to...

May1213 08:00 AM
Edi

6 
466 
Does the distance traveled by an object sliding down an incline plane pertain to the base or the hypotenuse of the...

May1313 02:43 PM
jmosque

3 
425 
This is probably a simple question, but here is a little background from which to view the problem. A cellphone tower...

May1313 03:02 PM
mathman

1 
432 
Im looking to do some projects with permanent magnets.
I dont have access to a gaussmeter and i'm wondering if...

May1113 10:24 AM
Wingwalker

2 
481 
Hey guys, I want to know if I have an equation on thrust correct. I figured whats the acceleration as a function of...

May1113 01:23 PM
D H

9 
910 
Hello everyone,
I am a recent horticulture graduate and as such, I take a long time figuring out physics...

May1113 12:07 PM
bob5bob

0 
437 
For a monoatomic ideal gas, if ##c_v## is constant then the internal energy is worth ##U=\frac{3nRT}{2}##. This is a...

May1113 10:24 PM
fluidistic

6 
811 
First of all, if you have a generator with an open circuit, and you are pedal powering it, where does the energy go? I...

May1213 09:08 PM
russ_watters

7 
1,399 
I am revisiting a topic discussed in earlier threads, because I feel the answers given there are either...

May1213 06:46 AM
Jano L.

5 
999 
Let's say you have a strong spherical neodymium magnet (for the purposes of this example, let's give it a 1 cm...

May1313 05:20 AM
lightarrow

2 
658 
This might be a bit philosophical, but is this just from experiment? that for a really really smooth surface, people...

May1413 08:07 AM
Chestermiller

14 
1,152 
Hi, I am trying to design a lens system with 20 degrees FOV that can focus light onto an image plane that is 0.2 mm...

May1313 01:45 AM
semc

0 
282 
Is the laser perfect monochromatic light source?

May1113 03:53 PM
Andy Resnick

2 
874 
The Legendre transformation creates a new function which contains the same information as the old, but is of a...

May1113 05:36 AM
Trifis

16 
13,830 
Hi all,
My question concerns the theory of how super resolution microscopy causes a frequency shift to allow...

May1413 07:58 AM
u0362565

3 
665 
I've read a lot about the mole , avogadro's no. , molecular mass and such , but I can't seem to understand anything ,...

May1213 02:13 PM
kira506

10 
904 
I just noticed that torque has dimensions of energy! What does that mean?

May1113 05:45 AM
Viru.universe

3 
560 
I understand the Gibbs Free Energy equation that was drilled into us in Chemistry class but not even my teacher could...

May1113 09:56 PM
morrobay

11 
1,044 
Hi all,
I have a question about airy patterns and how these determine resolution in images. So to increase...

May1413 07:33 AM
u0362565

10 
986 