INSTRUCTIONS: Solve the following. Show your solutions in the answer sheet. 1. A roller coaster car reaches a maximum height of 45 m before moving downward. What is the speed of the car at the lowest point of the track? If the kinetic energy of the car at its lowest point is 6.25 x 105 J, what is the mass of the car? 2. A ball is dropped from the rest at the top of a building. It reaches the bottom of the building after 15 seconds. What is the speed of the ball before it hits the ground?