A 14 kilogram box slides down a long, frictionless incline of angle 30 degree. It starts from rest at time t = 0 at the top of the incline at a height of 21 meter above ground.
(a) Find the original potential energy of the box relative to the ground?
(b) From Newton's laws, calculate the distance the box travels in 1 second and its speed at t = 1 second.
(c) Calculate the potential energy and the kinetic energy of the box at t = 1 second.
(d) Calculate the kinetic energy and the speed of the box just as it reaches the bottom of the incline.