Can there be a phenomenon called negative gravitation?

Question

Say , if a rigid planet is rotating with the angular velocity " W" such that W> (R/g)^(1/2) , (R = radius of planet, g = acceleration due to gravitational force). Then according to the equation g'= g-(W^2 R), the value of g' will be negative and does a negative force of gravity. My question is that am I faultering in my assumptions?

We know that hypothetically it is said that gravity at equator will become zero if earth rotates with 17 times its present angular velocity.

Answer 1

That's not negative gravitation, that's a negation of one force with a different force.

As for actual negative gravitation, current cosmological theory has stuff called "dark energy" which is causing the universe to expand faster:
http://en.wikipedia.org/wiki/Dark_energy

Answer 2

It is the force exerted by earth and it pulls an object towards it at an acceleration of mass(in pounds of the object)x32 ft/secxsec.

So there can be force in this direction only.

From this stand points there is no negetive gravitational phenomenon.

But we are able to throw things up, break this so call gravity and have landed on moon.

Hope this answers the question.

Answer 3

I think you are actually trying to compare apples to oranges.
Regardless of the rotational forces, gravity will remain the same - whether it holds you on earth or is exceeded by the centripetal force.

I have often wondered, however, if it isn't "negative gravity" that keeps the people in the southern hemisphere attached to the earth....at least relative to the gravity that keeps me attached in the northern hemisphere.

Answer 4

yep centrifugal force will become equal to the gravitational force but you ain´t altering gravity for real just cheating it by changing your reference plane and system of force

Answer 5

Your reasoning is correct, but it isn't negative gravitation, it is negative apparent gravitation, not the same thing at all.

Answer 6

Hi. You are confusing gravity and centrifugal (or centripetal) force.