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

Apr2211 05:26 AM
ZapperZ

1 
47,867 
Three weeks ago I have constructed this apparent paradox inside the Newtonian world.
...

Mar207 12:31 PM
ZapperZ

514 
41,892 
I'm just confused...
I know that magnetic fields can do work only on pure magnetic dipoles like a bar magnet. Based...

Aug3112 07:17 AM
harrylin

407 
38,344 
I came across this Wikipedia article about Reactive Centrifugal Force. It seems to be saying that this is not the...

Sep2811 12:35 PM
D H

403 
36,348 
So I just watched Walter Lewin's lecture titled "complete breakdown of intuition". If you google it you can find it...

Apr811 11:20 AM
yungman

347 
38,636 
Hallo everyone,
Can a magnet do work on another magnet? (I believe it can. Just wanted to make sure.)
What...

Sep812 12:39 AM
Miyz

269 
24,124 
Title says it all.

Apr3014 09:28 AM
rkmurtyp

164 
15,730 
It is known that a voltage must be applied around a closed circuit to make current pass through it. So thats why a...

May211 10:59 AM
RedX

161 
11,058 
Hi,
I would like to calculate the torque on a color square screw full with water like the drawing show. All grey...

Mar2012 02:25 PM
Gh778

161 
6,033 
The version of Faraday's Law which purports to include both motional EMF and transformer EMF for circuits is false. ...

Mar1010 01:31 PM
Per Oni

155 
23,695 
This is a simple question, and I'm sure it has a trivial answer, but this thought occured to me just now.
How is...

May1212 12:31 PM
TurtleMeister

148 
18,116 
Mod note: This thread on the reactive centrifugal force was split from this thread on the (fictitious) centrifugal...

Feb1213 01:13 PM
DaleSpam

146 
8,268 
I had an interesting challenge earlier this year in physics class, and I got a good grade on my answer, but I'd like...

Dec2111 11:35 AM
Studiot

140 
16,477 
Is there a mathematical relation for the temperature change when a fluid flows through a pipe from one end to another?...

T 12:18 AM
Jay_

138 
9,974 
Hypothesis
A contained body of gas that is within a field of gravity will have differing temperature in differing...

Jan3012 02:36 AM
striphe

137 
14,309 
I've been having a huge debate about this, some people are saying "air resistance" and that just makes zero sense to...

Jun2211 08:08 AM
Doc Al

134 
16,370 
If they're orbiting Earth, then they're in uniform circular motion. And if they're in uniform circular motion, then...

Apr2213 05:48 PM
sophiecentaur

131 
7,576 
Hello physics forum crew, I would like some help coming up with one of those "is this possible" type questions.
...

Jul1912 09:54 AM
Darwin123

129 
9,786 
I think that there is no such thing as centrifugal force .
Am I right ? is this force fictitious ?

Feb213 07:29 PM
stevendaryl

128 
8,189 
I am reposting this question here in a new thread as Humber mistakenly posted it in a two year old thread.

Jan412 08:43 AM
D H

124 
8,390 
If I were to attempt to prove that the dot product of an electric and magnetic field is invariant under the conditions...

Dec1303 05:20 AM
lethe

120 
8,496 
Ok, I have a general question about centrifugal force.
Lets say I have an object who moves in a circular path, we...

Jul708 12:05 PM
cristo

117 
15,433 
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 
10,482 
I've just got some small problems this time.
The first being,do the particles at the axis of a rotating body really...

Aug1309 03:00 AM
BobbyBear

115 
8,920 
Thread split from this thread.
Not true.
The spray can is generating a constant force, not a constant power....

Sep310 08:42 AM
Dickfore

114 
11,509 
I am new here and have always loved the history of science as much as the science itself. I have been intrigued by...

May610 09:11 AM
James A. Putnam

113 
10,067 
We have some unbelievable discussions regarding the acceleration of race cars.
At first glance, many just look at...

Apr609 10:24 PM
russ_watters

108 
20,925 
I never really thought about this until the other day when someone asked me why something accelerating towards a...

May1105 05:40 PM
learningphysics

107 
6,126 
I know very little about physics, so I hope this is a pretty easy question.
Action is always acting and reaction is...

Oct708 06:26 PM
Andrew Mason

107 
10,850 
hi,
I'm having trouble understanding what the difference is between the B and H fields. What my understanding is, if...

Sep1313 11:21 AM
rebel rider

107 
33,523 
The following discussion emerged under the topic "at rest" in Einsteinian relativity, and while out of place there it...

Apr3012 04:28 AM
Ken G

107 
7,819 
Why does the air flow faster over the wing? In my fluid mechanics course we used streamlines and a half body to show...

Feb1212 10:16 PM
Stan Butchart

105 
18,590 
Today we did an experiment with a solenoid through which we varied the current. Around this solenoid, was a different...

Sep2412 05:44 AM
Qreeus

103 
7,289 
Then what makes an airplane fly?

Apr505 08:39 AM
Doc Al

97 
14,402 
I'm confused about Maxwell's Equations.
1) does an electrical charge (say, an electron) traveling with a constant...

Apr1210 03:29 AM
elect_eng

95 
8,119 
Trying this again from a different angle...
Let's say we have a 120 Volt AC source. We'll call it a generator. ...

Mar111 09:39 AM
shoestring

95 
8,836 
I'm afraid I need some help on this one. We are studying rotational dynamics and I read in my textbook, the...

Feb1012 11:08 AM
Philip Wood

92 
22,491 
I would like to start a discussion involving how sound works. I've read plenty of websites but none can satisfy the...

Feb2511 07:34 AM
ymalmsteen887

92 
6,652 
I have a classical mechanics problem related to the constrained motion of a mass:
as per the attached graphics,...

Jan2314 08:56 PM
DaleSpam

89 
3,151 
Energy can be neither created nor destroyed.
What is energy?. ability to do work.
what is work ? work = force x...

Jul1107 08:45 AM
Doc Al

88 
10,084 
I have trouble understanding and visualizing this concept because I want to think of something tangible. I am not sure...

Apr2204 10:59 PM
Math Is Hard

87 
4,879 