How we calculate potential energy in best accuracy?

Question

This question may be a bit ridiciolus but let me explain. I'm not talking about the formula, I am talking about, what is the best accuracy of calculating the potential energy.

For example, let I want to calculate a object in my room. You know p.e = m.g.h.

Then Must I define the height variable h, relative to my room's ground, like 1 meters or relative to my apartment's ground like 20 metres or relative to sea level; 250 meters or relative to distance through Earth core (because gravity starts from there) like 6400 kilometers.

For instance in class our teacher defines h from the ground like 1.5 metres.

Or just P.E depends on relatively to the ground? If it is like that there will be more than one different values of P.E of an object? Will it fit to physics?

I am a bit confused.

Answer 1

Absolute potential energy is undefined.

Definition:The change in potential energy of the system is defined as the negative of work done by the internal conservative forces of the system.

The definition itself convinces us that only relative potential energy is defined.

For systems having internal conservative force like gravity, you are free to choose the reference position anywhere in space.