How many joules of gravitational potential energy does a person have after they went up stairs that are 10 meters tall? Assume the person has a mass of 60 kilograms. And assume this takes place on earth.

James is trying to prove newton's 2nd law of motion. he tries to move four different objects with different masses, shapes, and sizes from point a to point b. the objects are a toy car, a car, a refrigerator, and a kitchen table. after some experimentation, he finds that force is dependent on the mass of the object, rather than it's size or shape. the object that takes the most force to move is the