2. A 200-kg boulder is 1000-m above the ground. a) What is its potential energy when it is 1000-m above the ground? b) What is its kinetic energy when it is 1000-m above the ground? c) The boulder begins to fall. What is its potential energy when it is 500-m above the ground? Where did the "lost" potential energy go? d) What is the kinetic energy of the boulder when it has fallen 500-m? e) What is the kinetic energy of the boulder just before it hits the ground?​​