Is there proof gravity can not be a energy source?

[brian334]

Mr. Rat,
I generally agree with ever thing you post, but to prove gravity is not a energy source a few limited examples will not due.
My definition of energy is the ability to do work, or the ability to make things move.
Gravity clearly can make things move.

[ResinRat2]

So, Omnibus, I am trying to clarify what you mean by just the object.

If I were to take an automobile out of gas, and four strong men push it up a pretty steep hill for say a quarter of a mile to its top. Then these guys push it over the top of the hill and let it roll back down the other side (without stopping it at any time of course) then this is a violation of CoE in your definition?

[Omnibus]

So, Omnibus, I am trying to clearify what you mean by just the object.

If I were to take an automobile out of gas, and four strong men push it up a pretty steep hill for say a quarter of a mile to its top. Then these guys push it over the top of the hill and let it roll back down the other side (without stopping it at any time of course) then this is a violation of CoE in your definition?

Correct, it is a violation of CoE. At the top, because it can't be gotten there without moving it, that is, because of imparting velocity to it, the car will have both potential and kinetic energy. Now, once at rest at the top and then let go down the hill it will give back only the potential energy when reaches the foot of the hill. The kinetic energy will be lost. The energy balance along the closed loop ground-top-ground will be non-zero which is a violation of CoE.

[brian334]

I hate to get in the middle of a cat fight but will both Mr. Rat and omnibus stick to the topic.

[ResinRat2]

OK Omnibus, now please bear with me I have one more question.

If this same car was not out of gas, and drove to the top of the same hill, then at the top it turned off its engine and coasted down, would that be a violation of CoE by your definition. (without stopping at any time during this example).

Again, I am just trying to clarify what you mean.

Thanks

RR2