2. I drop a ball from rest off a 50m tall building. What is the speed of the ball right before it hits the ground? You can ignore air resistance. a. 11.1 m/s 15.7 m/s C. 31.3 m/s d. 44.3 m/s 3. A spring is attached to the ceiling of a room and is in its equilibrium position when a mass is attached to the spring and held at rest (still at the spring's equilibrium position). Which of the following best describes what is happening in terms of energy right after the mass is released? a. Gravitational potential energy and spring potential energy are both being converted into kinetic energy. Gravitational potential energy and kinetic energy are both converted into spring potential energy. Gravitational potential energy is converted into both kinetic energy and spring potential energy. d. Spring potential energy is converted into gravitational potential energy and kinetic energy. 4. A solid cylinder, a solid sphere, a hollow cylinder, and a hollow sphere are placed side by side on a ramp and released from rest at the same time. Which object will reach the bottom first? The solid cylinder. b. The solid sphere. c. The hollow cylinder. d. The hollow sphere. e. Not enough information to determine which reaches the bottom first. 5. A 250g hoop is rolling without slipping across a flat table with a linear speed of 4m/s. How much kinetic energy does it have? 1 J "2 J C. 3 J 4 J 8. A 3kg cart is traveling to the right at 3m/s when it collides and sticks to a 2kg cart traveling to the left at 5m/s. Which of the following statements is true? After the collision the carts will be traveling to the left. The collision was an elastic collision. b. After the collision the carts will be traveling to the right. The collision was an inelastic collision. After the collision the carts will be traveling to the left. The collision was an inelastic collision. d. After the collision the carts will be stationary. The collision was an inelastic collision. 9. An ice skater is performing a spin during their Olympic debut. They initially have their arms and legs tucked in close to their axis of rotation. What happens as they extend their arms and one leg out away from their axis of rotation? a. Their angular momentum increases, moment of inertia decreases, and angular speed increases. b . Their angular momentum decreases, moment of inertia increases, and angular speed decreases. Their angular momentum is constant, moment of inertia decreases, and angular speed increases. Their angular momentum is constant, moment of inertia increases, and angular speed