Question

When is the gravitational potential energy of a body is positive or negative?

Answer 1

Near-surface of Earth, we use U = mgh to find the gravitational potential energy of an object. And we say that as it goes higher, the gravitational energy increases. Namely, that a 1.0-kg object on the ground has 0 J of energy and if it is moved to 1 m above the ground it would now have +10 J of gravitational potential energy (give or take).