A 2-kg box slides down a long, frictionless incline of angle 30°. It starts from rest at time t = 0 at the top of the incline at a height of 20 m above the ground.

(a) What is the original potential energy of the box relative to the ground?

(b) From Newton's laws, find the distance the box travels in 1 s and its speed at t = 1 s.

(c) Find the potential energy and the kinetic energy of the box at t = 1 s.

(d) Find the kinetic energy and the speed of the box just as it reaches the bottom of the incline.