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

Apr2211 05:26 AM
ZapperZ

1 
41,737 
Hello, I'm have just started on this subject, and I am confused with the following equation:
since E(t) = kq(t)
...

Oct709 01:36 AM
nnnm4

2 
607 
I am currently studying surface tension. I came across a topic named "capillarity" where it is said that mercury falls...

Oct811 12:50 PM
Studiot

2 
889 
Hello,
For a reversible heat engine between temperatures T_1 and T_2, the ratio of heat going in and out the engine...

Sep2310 06:48 AM
DrDu

116 
9,613 
What is a contraption I can make at home somewhat easily to apply a constant force to a block? I am doing an...

Nov913 08:48 PM
K^2

6 
390 
Hello
i know how to derive the components of acceleration in other coordinates like spherical
start here :...

Jan112 09:16 PM
world line

4 
1,098 
Hi !
My name is Max and I'm a Mechanical Engineer.
I'm working on Control Moment Gyroscope project, but because for...

May2412 10:00 AM
jon110334

1 
1,998 
When someone mentions exploatation of an electric (electrostatic) energy from clouds one would instantaneously imagine...

May1308 12:58 AM
haneesh17

11 
2,022 
Hi.
Suppose I have 2 cylindrical bodies of the same radius and length  one is a good thermal conductor, while the...

Oct1513 08:28 AM
dreamLord

10 
814 
I have a question....
Suppose you have a thin and long rectangular piece of aluminum.
You heat one end (pt A)....

Nov2911 11:50 PM
sonofptolomey

3 
1,320 
For extended surface or fin, how do we find the convection coefficient ? Explain some general idea? thanks

May811 12:58 PM
edgepflow

1 
637 
Imagine Two cylinders One inside another with air in between them.There is a cutout made in the Outer cylinder.The...

Oct2712 02:50 AM
sriram123

0 
566 
hi,
if i have a cylindrical rod of copper and i heat is at one end face while the other surface areas are open to...

Sep3011 07:06 PM
gsal

2 
4,430 
I am working on a problem involving heat transfer from a horizontal pipe in air. I am having trouble with it and not...

Feb2410 02:48 PM
hemi_fan

0 
4,217 
Hello everyone, new guy here.
I'd like some other minds on an ongoing debate i have with quite a few people....

May2108 06:28 AM
Fearless

2 
4,628 
Hey, I was doing some revison for a test and i came across this question which I cant get my head around
a...

Jan1612 11:18 AM
AlephZero

5 
1,194 
Hi. I'm trying to make a simple model of a condensation based countercurrent heat exchanger where liquid water and...

Apr111 07:59 AM
Kelju Ivan

0 
1,357 
Just a couple of questions on conventional current that have been troubling me...
Firstly, does conventional...

Nov1704 09:56 PM
rayjohn01

2 
4,143 
Alas, another one of my conceptual struggles in regards to current. In regards to a circuit in which a solid metal...

May809 11:54 AM
chroot

45 
3,264 
I have a complex mathematical model (about 2000 lines of code) which calculates heat exchanger performance.
Using...

Nov1308 07:04 PM
Redbelly98

4 
953 
Why do all rays coming from far off distance from a source(may be planar)... converging at a point need to travel the...

Dec1807 12:56 AM
pardesi

4 
1,022 
If you want to calculate the electric field at a distance r from a line of infinite length and uniform charge density...

Nov2704 12:50 PM
krab

4 
1,421 
does anyone know how to build a convergent nozzle, i.e. the calculations equations etc?? please help. i wanna use it...

Jan1513 01:20 AM
scumhearted

0 
605 
what happen if converging rays are made to pass to a convex lens?
what happen if divergent rays are made ...

Oct711 11:30 AM
chrisbaird

1 
888 
I hope this is the right place to ask this. It is an experiment question.
I have a 785 nm laser and a 1550 nm laser...

Y 04:38 AM
UltrafastPED

4 
134 
What am I missing here?
A person looks at a gem using a converging lens with a focal length of 15.0 cm. The lens...

Aug2504 09:03 PM
soccerjayl

2 
7,641 
I'm in the middle of studying for the MCAT, and just want to get all the concepts instead of memorizing how to solve...

Mar3110 04:55 AM
Doc Al

1 
1,477 
Suppose a rod is rotating about its center of mass, for simplicity consider it to be its geometric center(uniform...

Feb813 10:36 AM
sophiecentaur

11 
1,454 
is it possible to convert internal energy into mechanical energy? is there some real life example which can explain...

Apr1509 09:04 PM
maverick_starstrider

2 
701 
So suppose we have two objects, both with positive charge Q Coulombs and X meters apart.
And now suppose Object 1 has...

Dec211 07:11 PM
lluke9

0 
1,171 
Suppose there was a mass, m1, traveling rightwards at v0. There is a second mass, m2, above the line of motion of m1,...

Dec712 05:17 PM
appa609

2 
794 
If we have capacitance of 1840 Farads/gram, how much Wh/kg (energy density) it will be?
How it applies to...

Mar2511 09:19 AM
Stanley514

2 
2,609 
Hello,
I am trying to extract the 3 angles from a unit vector to position a part on a 5 axis milling machine:
...

Sep2810 05:10 AM
Dan B

2 
4,796 
hi folks,
in statistical mechanics one can see for example:
\int exp(\beta H(x,p)) dx dp = \int \Omega(E)...

Jan1612 11:49 AM
Derivator

0 
1,087 
How to convert density from mol/L to kg/m3?

Feb2708 02:18 AM
Stupid_Engine

3 
29,676 
Hello,
Is there a formula to convert a certain radio frequency to temperature? Thanks.

Nov2007 07:07 AM
DaleSpam

3 
6,273 
If I have a vector for the angular momentum of a ball rolling along a plane in terms of the world and I wan't to...

Jan2808 02:41 AM
Bobolis

0 
6,065 
Is there any known method to convert straight into electrical energy?
without all that 'steam' part? xD

Oct1512 08:10 PM
russ_watters

8 
881 
Problem: A nuclear generator produces energy used to accelerate a rocket. Given energy and mass, what is the...

Aug2113 11:09 PM
eigenperson

2 
485 
I am wanting to accurately calculate the top speed of a car (using it's power, mass, drag, and friction). I started...

May3008 06:20 PM
rcgldr

3 
14,181 
Hello,
For a given vehicle, I want to use a given chart for engine torque vs. engine speed (or hp vs. engine speed)...

Apr310 04:13 PM
rcgldr

1 
3,310 