
#1
Sep1304, 04:15 AM

P: 2

Can anyone help me on this?
If I have a very large ball (ball A) and a tiny ball (ball B) as such that ball B is attracted by the center of ball A, then theorically, if ball A is a perfect sphere I could expect ball B to start spinning on ball A and never stop as ball B won't have anywhere to rest on ball A. Am I right? In fact, this would be the opposite of antigravity and by multiplying that force we could extract an energy that could eventually move an object. 



#2
Sep1304, 04:39 AM

Mentor
P: 7,292

Actually we routinely extract energy, and nearly endless from a combination of the suns heat and gravity. The sun evaporates sea water, it falls in the mountains as rain. We dam the streams and generate electricity.
As for your balls, I have no clue what you are talking about but I can be sure that it will not work. Simply because you are talking about a free lunch. TANSTAAFL. 



#3
Sep1304, 05:52 AM

P: 76

What you think is wrong because ball B WILL rest on ball A, because the gravitational forces will not help ball B to roll along the side of ball A. The force on ball B is drawn towards the centre of ball A, which makes the two stick.
I don't see why ball B should start spinning around. 



#4
Sep1304, 09:35 AM

Sci Advisor
HW Helper
P: 3,149

Gravity forces converted to energy
The Earth is like a big ball. Place a small ball such as a bowling ball someplace on the Earth's surface and let us know whether it spins out of control! :)




#5
Sep1304, 12:14 PM

P: 698

ya, the ball would not spin around the other ball since the force between the two balls is directly perpendicular to the intersection tangent. Theregore, there would be no force to push the ball in one direction or another.




#6
Sep1304, 08:11 PM

P: 142





#7
Sep1304, 08:12 PM

P: 4

[tex]v(average) = \frac{s}{t}[/tex]
[tex]a=\frac{vu}{t}[/tex] [tex]s=ut + \frac{1}{2} a t^2[/tex] [tex]v^2=u^2 + 2as[/tex] 



#8
Sep1704, 10:48 AM

P: 2

but what if I push two balls against each other? They can't possibly stick together. This is what I mean.




#9
Sep1704, 11:09 AM

P: 104

As long as you still apply force to both balls directly towards each other they will touch at a tangent point and stay that way unless the force changes direction.



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