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Again, for some odd reason, people...

Apr2211 05:26 AM
ZapperZ

1 
47,797 
We all know the air at the ceiling is warmer than the air at the floor because "hot air rises" due to the density...

Jul113 07:28 AM
NascentOxygen

5 
2,384 
What would happen if you take the wedge of the magnetic field and the velocity of a charged particle, you get the...

Jul113 12:09 AM
WannabeNewton

11 
552 
How in microscope there is a phenomena of differaction, and in case of telescope there is interference of light...

Jun3013 05:27 PM
sophiecentaur

3 
523 
Hello dear PFmembers! :shy:
I'm looking for some appropriate formula which could be utilized to calculate the...

Jun3013 02:15 PM
Gliese123

6 
1,101 
If I put vents on the hood of my car and drove at 60mph what kind of psi could be achieved? I don't care about what...

Jun3013 12:13 AM
Baluncore

4 
824 
I am trying to resolve some long standing problems I have encountered with blackbody radiation. Namely, the derivation...

Jun2913 11:20 PM
klawlor419

2 
654 
As far as I know, Cherenkov radiation occurs when a charged particle travels through a medium at a greater phase...

Jun2913 11:14 PM
jlefevre76

4 
804 
So we all know the Coriolis effect isn't demonstrated in a bathtub or toilet. Are there any videos online of the size...

Jun2913 06:42 PM
Bobbywhy

1 
485 
Hoping someone finds this problem interesting, I'm looking for some ideas on how to solve a real world problem, not a...

Jun2913 06:03 AM
Pigkappa

2 
415 
The vector magnetic potential is given
\vec A=\frac{\mu I}{4\pi}\oint\frac{e^{j\beta R_1}}{R_1}dl'
After a few...

Jun2913 04:31 AM
yungman

6 
487 
If someone is walking across the log (rod) of a bifilar pendulum, how would the period of oscillations be affected if...

Jun2913 02:16 AM
AkumAng3l

0 
934 
The other day, I was learning about creating "artificial" gravity by building a gigantic circularly shaped ship which...

Jun2813 04:37 PM
sophiecentaur

31 
2,448 
If you drop an object from a great height with no air resistance. e.g. 1000 km above the moon. How long will it take...

Jun2813 11:03 AM
MisterX

3 
553 
Hello, I have some trouble understanding an expression for the magnetic field energy .There are basically two...

Jun2813 04:59 AM
facenian

1 
495 
I've heard two hypothesis:
1. The air causes the image of the moon to literally appear larger
2. The increased size...

Jun2813 04:23 AM
sophiecentaur

24 
1,870 
I understand why the leading edge of a projectile creates a Mach cone in front of which the air is undisturbed. But...

Jun2813 03:40 AM
Baluncore

1 
484 
I have a theoretical question which I would like to brainstorm, and would appreciate any assistance.
Let's say...

Jun2813 03:17 AM
Bobbywhy

2 
481 
I am reading 'Classical Dynamics: A Contemporary Approach' by J. Jose, and I am confused about a step in the author's...

Jun2713 06:52 PM
facenian

1 
458 
Hi,
I'm reading about the equipartition's energy theorem (classical statistics), and I was wondering about its...

Jun2713 06:33 PM
Jorriss

4 
482 
From what I've learnt, the pressure increases when the area is reduced. Taking the high heels as an example, the tip...

Jun2713 05:44 PM
sophiecentaur

2 
476 
"when we apply AC to an inductor (pure inductance), the current will lag the applied voltage by 90 degrees. "
how...

Jun2713 05:30 PM
sophiecentaur

2 
473 
Hello!
I have another idea for how to break the second law of thermodynamics, and I don't see where this one cracks...

Jun2713 09:25 AM
Vanadium 50

3 
471 
Hi!
I have an idea for how to break the second law of thermodynamics, and I don't see where it cracks. I would...

Jun2713 08:44 AM
Bobcent

23 
1,695 
Sorry if the formulation is imprecise, I'm a biology major trying to study some physics. The question is:
So far,...

Jun2713 07:39 AM
boneh3ad

3 
955 
Suppose we have two sticks held in a vertical plane, pivoted at one point (check the diagram). If we let go, why is...

Jun2713 06:36 AM
dreamLord

15 
1,122 
Hi I have a couple of questions relating to these topic hope you guys can help :)
Comparing ethanol and water,...

Jun2713 04:29 AM
sgstudent

16 
1,793 
Why is it that the magnetic component of light interacts more with metamaterials than with naturally occurring...

Jun2713 03:23 AM
mfb

1 
355 
Hello,
I am a 15 year old high school student, We were being taught about current, My teacher said its a scalar...

Jun2713 03:00 AM
vanhees71

16 
1,135 
Hello All,
I have measured acceleration data from the sprung mass of vehicle, travelling at (almost) constant speed....

Jun2713 01:53 AM
tduell

0 
358 
I have always wondered about equal and opposite. If I had a rifle with a cartridge in the middle of a barrel, with two...

Jun2613 09:46 PM
Nugatory

5 
2,090 
Say ##V_{out}=4e^{j\frac {\pi}{6}}##, what is this mean? It is a scalar voltage.
Does this means:
4e^{j\frac...

Jun2613 05:01 PM
Khashishi

1 
416 
Hey! I have a project where I'm building a car running from direct sunlight only using solarpanels and bike hub...

Jun2613 03:15 PM
Bindle

10 
751 
In chapter 51, volume 1 of the FLP, Feynman writes
Unfortunately he didn't give a justification for this claim. I...

Jun2613 02:20 PM
dEdt

6 
541 
I got a pretty basic question about the thermodynamics of air cooling water. I have a liquid cooling system for my...

Jun2613 01:47 PM
CWatters

6 
1,034 
Hi everyone
Can someone point me in the right direction here please. Happy to do the digging, but so far I can't...

Jun2613 04:07 AM
CWatters

2 
659 
In the Princeton Review for AP Physics, there is a question on calculating the effective spring constant when two...

Jun2613 12:35 AM
wotanub

2 
481 
I have been trying to derive a formula for the forces acting on and the centre of gravity of objects in a one...

Jun2613 12:07 AM
Droctagonopus

2 
449 
Hi,
I have been trying to find analytical solutions for a finite rectangular sheet, say, in the xy plane, with...

Jun2513 10:10 PM
Simon Bridge

1 
694 
If I had to push a box with a certain weight 'm' up an incline, would I just need a force 'slightly greater' than...

Jun2513 06:29 PM
PhanthomJay

9 
477 
This is a similar answer to a closed thread, which asked for the amplitude of a pendulum as a function of the bob's...

Jun2513 05:36 PM
bgc

0 
358 