if you spin a ball which is wet,the water spins off. F=mg .What is gravity 9.81 m/s What force is pulling down ?Is it electrons pulling us down and objects.Or is it the earth core molten magnetic field?
2006-09-14 09:53:11 · 10 answers · asked by mark r 2 in Science & Mathematics ➔ Physics
There are many theories but no absolute answer. We can explain the force of gravity of any body on another using Newton's Law of Gravitation:
F = GMm/r^2
What we do know is that the force of gravity is directly proportional to mass over distance squared.
Gravity on earth accelerates object (on average) at 9.81 m/s^2. On the Sun, Venus, Pluto, asteroids, etc. the acceleration due to gravity is different. You can figure out the acceleration due to gravity for any body by deriving from Newton
F = ma = GMm/r^2
cancel out the small m's (attracted body)
F/m = a = GM/r^2
so, the acceleration from gravity for any body (ANYTHING with mass) is:
a = GM/r^2 (where G is Newton's gravitational constant, M is the mass of the body, r is distance from it)
Someday we may know exactly how gravity works, but we definitely are not sure right now.
2006-09-14 10:10:10 · answer #1 · answered by AresIV 4 · 0⤊ 0⤋
Einstien died before he could figure out gravity. He explained it as deforming space - an example, get a rubber sheet and stretch it over a round barrel end. If you roll a marble across, it goes straight.
If you put a bowling ball in the center, the membrane curves. Now if you roll a marble across the top, it curves and starts spinning around the bowling ball - the ball is NOT attracting the marble, it is just bending the membrane. He said gravity was like this, and it explains the mechanics, but does not day what gravity is...
With today's 11 dimensional space, M theory, Ed Witten, Stringy Universe, etc, you can search these terms and find out what gravity is now going to be. We cannot escape our BRANE to affect other universes beside us, but gravity is the only thing we experience that can. Thus a huge gravity wave from a nuclear blast ( over 600 since 1940's ) will reach out and blast other BRANES, alerting other universes that we are here.
With the physics of the 11 dimensions being figured out, we may be able to, for the first time, discover the mechanics of gravity.
Experiments at CERN in the Large Hadride collider are helping to find missing particles and forces that would continue where Einstien left off, and open an entirely new look at gravity.
2006-09-14 10:18:42 · answer #2 · answered by robertta g 2 · 0⤊ 0⤋
To answer the first question:
No one really knows why gravity works. There are alot of plausible ideas and theories, but we really are not sure at this time what exactly gravity is. This may seem wierd as it is about the most ordinary and everyday of the fundamentaly forces, but it is true. I will confidently say that gravity has absolutely nothing to do with electrial or magnetic forces, as this is a totally different fundamental force.
Now for the second question.
Centrifugal force is not a real force but an imaginary force that the water feels in its accelerating reference frame. The water's own momentum is what keeps it in the bucket, not centrifugal force.
2006-09-14 10:39:01 · answer #3 · answered by msi_cord 7 · 1⤊ 0⤋
If the bucket was hanging from a rope and you simply spin the bucket like a ball, gravity would hold the water in the bucket until the water started spinning like a whirlpool in the bucket, at which time the water may start spilling out over the top. On the other hand, if you hold the bucket by the handle and you spin around then centrifugal force, which is a motion forced gravity, holds the water in the bucket.
2016-03-27 01:32:05 · answer #4 · answered by ? 4 · 0⤊ 0⤋
Because the force of gravity performs work, it must have an energy source. There is the physics trilogy that describes this force. It is E = mc2, m = E/c2, and c2 = E/m. The last is that for a field of physical time, or a gravitational field - they are the same. The "E" value here is that of the heat energy contained within our planet. If there were no heat energy, then there would be no gravitational field. This form of energy does not exist of itself. If there were no energy source, then there would have to be a continual creation within all matter at all times in order for this force to exist. http://360.yahoo.com/noddarc there is a short writing "The Problem and Repair of Relativity" that will describe this force accurately.
2006-09-14 10:35:20 · answer #5 · answered by Anonymous · 0⤊ 2⤋
Relativity says it is due to a curvature in space-time. Quantum physics says it is caused by a particle called a "graviton". Scientist really don't know, but if they find out, they will be able to unite the two theories which conflict with each other.
2006-09-14 10:01:12 · answer #6 · answered by The Doctor 7 · 0⤊ 0⤋
Hi. One theory is that the effect is caused by the mass causing curvature of the surrounding space. Think of a deck of cards being bent between two fingers. The cards "want" to move towards the center of curvature.
2006-09-14 09:56:23 · answer #7 · answered by Cirric 7 · 0⤊ 0⤋
Like Evolution, it's only a theory. It's not real!
2006-09-14 10:02:10 · answer #8 · answered by Anonymous · 0⤊ 0⤋
Do you know I've always wondered that myself but was too busy getting on with my life to ask!
2006-09-14 09:56:06 · answer #9 · answered by Anonymous · 0⤊ 1⤋
very good question i have been wondering that myself
2006-09-14 09:56:38 · answer #10 · answered by Anonymous · 0⤊ 0⤋