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## Main Question or Discussion Point

Maybe i am looking at things wrong, but it seems that classic physics cannot tell me how much gravitational energy an object has at "rest", when it is at the ground potential- at zero.

Example. I have a table. I place a 100 kg object on the table. What is the gravitational energy of the object exerting on the table? The ground potential is the table top, not the ground. Classic mechanics does not seem to provide me an answer. PE = mgh does not work because i get zero. This is not right because it is obvious downward energy is being exerted on the table by the 100 kg weight. PE = mg does not work because if the object is raised above the table any distance less than a meter (such as 0.5 m), it will have a lower energy than the energy calculated at the ground potential- this is nonsensical.

This is bizarre. How come classic physics cannot calculate this? And how do i calculate? Do i use relativity or something? Or am i looking at the problem wrong?

I am stumped. Help, I need an expert! :surprised :surprised

Example. I have a table. I place a 100 kg object on the table. What is the gravitational energy of the object exerting on the table? The ground potential is the table top, not the ground. Classic mechanics does not seem to provide me an answer. PE = mgh does not work because i get zero. This is not right because it is obvious downward energy is being exerted on the table by the 100 kg weight. PE = mg does not work because if the object is raised above the table any distance less than a meter (such as 0.5 m), it will have a lower energy than the energy calculated at the ground potential- this is nonsensical.

This is bizarre. How come classic physics cannot calculate this? And how do i calculate? Do i use relativity or something? Or am i looking at the problem wrong?

I am stumped. Help, I need an expert! :surprised :surprised