Work, Power and Energy TEST 15. The diagram shows the path of a roller coast on a frictionless track starting from rest at point Q. The coaster slides down the frictionless track past point R, which is at ground level. Which of the following statements best describes the energy of the coaster from point Q to point R? A The potential energy at point Q becomes all kinetic energy at point R. B The kinetic energy at point Q becomes all potential energy at point R. C The total energy at point Q is greater than at point R. D The total energy at point Q is less than at point R. 16. A person is using a force of 200 N to push a box a distance of 4 meters, Calculate the power of the person if the box was moved in 10 seconds. A 80 Joules B 80 Watts C 800 Joules D 800 Watts 17. How much kinetic energy does that same sled from the question above have if it is moving with a constant velocity of 7 m/s and has a mass of 120 kg? A 2940 J B 1.33 J C 0.75 J D 300 J 18. The velocity of a 0.5 kg ball is 4 m/s. If the velocity is changed to 8 m/s, what happens to the kinetic energy? A The kinetic energy is twice as great B The kinetic energy is four times as great C The kinetic energy is half as great D The kinetic energy is one fourth as great E There is no change in kinetic energy 19. Choose the statement that accurately describes the interaction between the compressed spring and marble after the spring is released. A the elastic potential energy of the spring becomes chemical Spring Launcher energy of the marble Marble B the mass of the spring becomes the mass of the marble C the elastic potential energy of the spring becomes kinetic energy of the marble D the marble absorbs the springs elastic potential energy and Spring stores it as gravitational potential energy