Assignment task: Ronaldo having a mass of 75 kg starts skiing from rest at the top of a hill. He is at a height of 30 m from the ground. By neglecting friction, answer the following questions:
(a) Calculate Ronaldo's gravitational potential energy at the top of the hill relative to the ground.
(b) Calculate Ronaldo's total mechanical energy at the top of the hill.
(c) Calculate Ronaldo's kinetic energy and gravitational potential energy at a height of 15 m from the ground.
(d) Calculate Ronaldo's speed at the bottom of the hill.
(e) Sketch the variation of Ronaldo's total mechanical energy, kinetic energy and gravitational potential energy as a function of height above the ground on the same graph. Explain your reasoning carefully.