In your textbook, read about analyzing collisions. The diagrams show the motion of two identical 20-kg carts before and after they collide. Use the diagrams to answer questions 4-7. Circle the letter of the choice that best answers the question. Before After 20 20 A 20 20 10 m/s 0 m/s 0 m/s 10 m/s - 20 20 B 20 20 10 m/s 0 m/s -5.0 m/s 5.0 m/s - 20 20 20 20 10 m/s 0 m/s 5.0 m/s 4. In which collision(s) did the momentum of the system remain constant? a. only A c. A and C b. only B d. A and B 5. In which collision(s) did the energy of the system remain constant? . only A c. only C b. only B d. A, B, and C 6. An inelastic collision occurs in which collision(s)? a. A and B c. only B b. Band C d. only C 7. In the inelastic collision(s), what happened that reduced the total mechanical energy of the system? . Some kinetic energy changed to elastic potential energy. b. Some kinetic energy changed to gravitational potential energy. c. Some kinetic energy changed to chemical energy. d. Some kinetic energy changed to sound energy and thermal energy.SECTION 2 Conservation of Energy In your textbook, read about conservation of mechanical energy. 1. You are designing a skateboard park. The starting ramp is supposed to be 0.51 m high. a. What would be the gravitational potential energy for a 63.5-kg skateboarder at the top of the starting ramp? b. How could you change the ramp design so that a 63.5kg skateboarder moves twice as fast at the bottom? For now, ignore air resistance and friction between the skateboard and ramp. Explain why this design change would work in terms ofthe conservation of mechanical energy. c. Assume that the same 63.5-kg skateboarder in part 3 falls offthe side ofthe ramp. What is the kinetic energy from the skateboarder's falling motion just before she reaches the ground? 2. Consider the ramp in problem 1. Explain why the skateboarder has the same final kinetic energy whether she falls off the side of the ramp, plummeting downward, or whether she rolls down the ramp. Draw a diagram. 3. Give several examples of mechanical energy being converted to other forms. 16. A ball of mass 0.5 kg has 100 J of translational kinetic energy. What is the velocity of the ball? a. 20 m/s (2. 100 m/s b. 40 m/s cl. 400 m/s 1?. A ball traveling at 30 m/s has 900] of translational kinetic energy. What is the mass of the ball? a. 1 kg c. 9 kg b. 2 kg d. 30 kg In your textbook, read about stored energy and gravitational potential energy. For each statement beta w, write true or rewrite the italicized part to make the statement true. 18. If a baseball is considered a system, work is done on it by the pitcher's hand, gravity, and the bat. 19. The work done by gravity on a rising ball is mgh. 20. The work done by gravity on a falling ball decreases the hall's kinetic energy. 21. Ifthe height of the bat is considered the reference point, when the ball hits the ground, its gravitational potential energy is iess than 0 J. 22. Ifthe Moon and Earth are considered a system, the system's energy is stored as eiastic potentiai energy. 23. The work that an archer does when pulling back on a bowstring is stored as gravitationai potentiai energy. Use the diagram at right to answer questions 2426. The height of point C is 0. 24. The point at which the blockEarth system has both kinetic and potential energy is a.A b.B c.C 25. The block-Earth system has the maximum amount of kinetic energy at point a.A b.B c.C 26. At point A, the block-Earth system has . no energy a. b. both kinetic and potential energy c. only kinetic energy d. only potential energy