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

Apr2211 05:26 AM
ZapperZ

1 
47,035 
Hi, I have a question related to the DC motor that i hope you geniuses can help me with.
By Fleming's Left hand...

Sep2312 12:58 PM
sgstudent

6 
860 
Another intersting point on home electronics raised was  why does every device you purchase have it's own...

May1305 03:40 PM
zoobyshoe

39 
3,395 
hello ,
DC (I guess AC too) power supplies have 3 terminals: plus, ground, minus.
If I set the voltage to 30...

Sep2808 12:03 AM
Phrak

3 
8,966 
Hello, can someone please help me out here, i want to step up the voltage of a 1.5V battery to 300V, i know that to do...

Dec1207 03:53 PM
alvaros

1 
1,776 
de broglie wavelenth of a perticle approaches zero faster than 1/v as its speed approaches the speed of light..how can...

Oct809 02:02 PM
hasanhabibul

0 
588 
In order to understand about DeBroglie's explanation on Bohr's second postulate,concept of standing waves should be...

Apr1813 07:23 AM
Philip Wood

2 
996 
My textbook says that dETdS+PdV<0 for all irreversible processes. However, for reversible processes, the author says...

Jul1212 10:54 AM
Studiot

21 
1,257 
Are elemental particles subject to entropy? Are there dead electrons "no spin".

Dec711 03:18 PM
mathman

6 
1,238 
The noslip boundary value constraint for NavierStokes solutions was explained in my fluid dynamics class as a...

Apr3012 09:33 AM
Andy Resnick

1 
1,024 
Hi,
I've been trying to figure out a formula which describes the relation between the area, load and negative psig...

Jul2007 12:29 PM
deimors

2 
1,428 
Firstly, I'd like to announce that this is not a homework question, it is an example of a problem I thought up to...

Apr1009 04:24 PM
arildno

3 
2,013 
My question is what causes death wobble? Let me explain more...
The vehicle I've experienced this on is a Jeep with...

Aug2209 04:03 AM
rcgldr

19 
15,705 
Helloooo. I'm debating a creationist and he consistently is bringing up the laws of thermodynamics to try and 'prove'...

Jan406 08:03 AM
Doc Al

17 
2,920 
Just a question:
I do know it is possible to have a debye layer in a electrolyte. But is it posible to have a Debye...

Jul1506 12:24 AM
Clausius2

2 
4,861 
Hello, I am new here.
I was reading Wangsness electromagnetic fields and he delves into a short discussion about...

Jul3114 01:59 PM
IamStupid

0 
93 
Hello,
Here's my challenge: I want a physics model for how one would go about in order to decay the moon's orbit....

Dec213 09:45 AM
BruceW

10 
1,154 
Ok, so I was doing this problem, *NOT* a homework problem, where I was solving for the force (and eventually, the...

Jun1310 06:05 PM
russ_watters

2 
2,560 
Hi there, sorry for asking a question as my first post instead of contributing to the community however I have a...

Jun813 04:21 PM
Aero_UoP

4 
1,349 
I posted a question as thus :
A train moving at 100 km/hr uniformly decelerates at a rate of 10 km/hr each hr. How...

May507 09:13 AM
ZapperZ

7 
1,629 
A basis for any 3dimensional vector space must have 3 vectors in it.
So the acceleration of any object in ℝ^{3}...

May213 02:54 PM
AlephZero

6 
736 
This is a short conceptual question.
If I place a heat sink in a sealed container, and than raise the ambient...

Sep610 06:18 PM
Dr Lotso'watts

4 
653 
Greetings everyone:
I am trying to create a software for estimating temperature for a liquid in a group of tanks...

Apr811 03:54 AM
sandeepbwes

0 
489 
In thermodynamics heat reservoir has a lot deegres of freedom. Can you tell me some examples of that deegres. Thx

Mar1912 11:35 PM
Andrew Mason

3 
762 
I was fascinated by the Wired article describing such an elegant engineering solution for remote data collection deep...

Feb2807 10:48 AM
russ_watters

4 
1,509 
See here:
http://www.physicsforums.com/showthread.php?t=299561
And:
...

Mar1409 06:18 PM
rcgldr

4 
1,057 
Living in the city, it seems that some jerk tries to merge right into my car on a daily basis during rush hour (i.e....

Jul1411 04:59 AM
rcgldr

5 
1,854 
Hallo everyone,
in electrostatic we have a linear realation between E D and P, i do understand that P
is related...

May1910 10:54 AM
Jano L.

15 
1,642 
This may seem obvious, but please define these for me, in as much details as possible.
What does it mean to:
...

Dec2411 12:45 PM
DaveC426913

16 
3,222 
Hi
I'm trying to define a Newtonian lagrangian in an
rotating reference frame (with no potential)
Something to...

Oct2209 12:55 AM
mtak0114

4 
4,679 
So I read somewhere that if we know u(s,v) i.e. internal energy as a function of entropy and specific volume, we can...

Dec913 01:43 PM
Jano L.

7 
660 
"Induction is a process of increment of charge such that the charge induced equals to the charge difference between...

May809 03:58 AM
dE_logics

5 
1,731 
I am designing an eddy current brake system for use in roller coaster design.
I have the flux density required to...

Mar2311 04:21 PM
os220

2 
1,866 
Electric field around a charge or system of charges is defined as the force experienced per unit charge. Won't the...

May3113 05:20 AM
Pushpam Singh

3 
581 
A block of mass m is resting on a frictionless surface and a push is given to it along the surface.
Now because of...

Aug1805 07:34 AM
HallsofIvy

2 
2,298 
Hello.
I have attached a file containing a detailed question regarding the definition of the electric current. I'll...

Apr2211 12:47 PM
AS28

2 
802 
Okay so I feel this is a bit of a weak first post in a forum but I haven't yet found a place for comment that wouldn't...

Nov2509 06:10 PM
cesiumfrog

3 
1,144 
We all know that the definition for work is
W = ∫F.ds
Why can't it be
W = ∫s.dF?

Jun811 02:23 AM
Studiot

9 
2,841 
I've been told (since high school I think) that "view angle" in a 2dimensional plane is approximately (distance to...

Jul2913 08:03 AM
Andy Resnick

6 
1,321 
Hello,
I have found the following definition in wikipedia:
A fluid is defined as a substance that continually...

Nov3008 01:25 PM
DaleSpam

2 
785 
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 
580 