A0.18kg apple falls from a tree to the ground, 4.0 {\rm m} below. ignore air resistance. take ground level to be y = 0. part a determine the apple's kinetic energy, k, the gravitational potential energy of the system, u, and the total mechanical energy of the system, e, when the apple's height above the ground is 4.0 m. part b determine the apple's kinetic energy, k, the gravitational potential energy of the system, u, and the total mechanical energy of the system, e, when the apple's height above the ground is 3.0 m part c determine the apple's kinetic energy, k, the gravitational potential energy of the system, u, and the total mechanical energy of the system, e, when the apple's height above the ground is 2.0 m