Base your answers to questions 5 and 6 on the information below.

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1 1. A car travels 90. meters due north in 15 seconds. Then the car turns around and travels 40. meters due south in 5.0 seconds. What is the magnitude of the average velocity of the car during this 20.-second interval? A) 2.5 m/s B) 5.0 m/s C) 6.5 m/s D) 7.0 m/s 2. How far will a brick starting from rest fall freely in 3.0 seconds? A) 15 m B) 29 m C) 44 m D) 88 m 3. A car initially traveling at a speed of 16 meters per second accelerates uniformly to a speed of 20. meters per second over a distance of 36 meters. What is the magnitude of the car s acceleration? A) 0.11 m/s 2 B) 2.0 m/s 2 C) 0.22 m/s 2 D) 9.0 m/s 2 4. Which graph best represents the motion of a block accelerating uniformly down an inclined plane? A) B) C) Base your answers to questions 5 and 6 on the information below. Projectile A is launched horizontally at a speed of 20. meters per second from the top of a cliff and strikes a level surface below, 3.0 seconds later. Projectile B is launched horizontally from the same location at a speed of 30. meters per second. 5. The time it takes projectile B to reach the level surface is A) 4.5 s B) 2.0 s C) 3.0 s D) 10. s 6. Approximately how high is the cliff? A) 29 m B) 44 m C) 60. m D) 104 m 7. Base your answer to the following question on the information below. An outfielder throws a baseball to the first baseman at a speed of 19.6 meters per second and an angle of 30. above the horizontal. Which pair represents the initial horizontal velocity (vx) and initial vertical velocity (vy) of the baseball? A) vx = 17.0 m/s, vy = 9.80 m/s B) vx = 9.80 m/s, vy = 17.0 m/s C) vx = 19.4 m/s, vy = 5.90 m/s D) vx = 19.6 m/s, vy = 19.6 m/s 8. A ball is thrown at an angle of 38 to the horizontal. What happens to the magnitude of the ball s vertical acceleration during the total time interval that the ball is in the air? A) It decreases, then increases. B) It decreases, then remains the same. C) It increases, then decreases. D) It remains the same. D)

2 9. A number of 1.0-newton horizontal forces are exerted on a block on a frictionless, horizontal surface. Which top-view diagram shows the forces producing the greatest magnitude of acceleration of the block? A) B) C) 12. On a small planet, an astronaut uses a vertical force of 175 newtons to lift an 87.5-kilogram boulder at constant velocity to a height of meter above the planet s surface. What is the magnitude of the gravitational field strength on the surface of the planet? A) N/kg B) 2.00 N/kg C) 9.81 N/kg D) 61.3 N/kg 13. A 0.50-kilogram puck sliding on a horizontal shuffleboard court is slowed to rest by a frictional force of 1.2 newtons. What is the coefficient of kinetic friction between the puck and the surface of the shuffleboard court? A) 0.24 B) 0.42 C) 0.60 D) A stone on the end of a string is whirled clockwise at constant speed in a horizontal circle as shown in the diagram below. D) 10. Which object has the greatest inertia? A) a 15-kg mass traveling at 5.0 m/s B) a 10.-kg mass traveling at 10. m/s C) a 10.-kg mass traveling at 5.0 m/s D) a 5.0-kg mass traveling at 15 m/s 11. Which situation describes an object that has no unbalanced force acting on it? A) an apple in free fall B) a satellite orbiting Earth C) a hockey puck moving at constant velocity across ice D) a laboratory cart moving down a frictionless 30. incline Which pair of arrows best represents the directions of the stone's velocity, v, and acceleration, a, at the position shown? A) B) C) D) 15. An unbalanced force of 40. newtons keeps a 5.0-kilogram object traveling in a circle of radius 2.0 meters. What is the speed of the object? A) 8.0 m/s B) 2.0 m/s C) 16 m/s D) 4.0 m/s

3 16. Calculate the magnitude of the average gravitational force between Earth and the Moon. [Show all work, including the equation and substitution with units.] 17. A 5.00-kilogram block slides along a horizontal, frictionless surface at 10.0 meters per second for 4.00 seconds. The magnitude of the block's momentum is A) 200. kg m/s B) 50.0 kg m/s C) 20.0 kg m/s D) 12.5 kg m/s 18. Which quantity has both a magnitude and a direction? A) energy B) impulse C) power D) work 19. When a 1.0-kilogram cart moving with a speed of 0.50 meter per second on a horizontal surface collides with a second 1.0-kilogram cart initially at rest, the carts lock together. What is the speed of the combined carts after the collision? [Neglect friction.] A) 1.0 m/s B) 0.50 m/s C) 0.25 m/s D) 0 m/s 20. How much work is done by the force lifting a 0.1-kilogram hamburger vertically upward at constant velocity 0.3 meter from a table? A) 0.03 J B) 0.1 J C) 0.3 J D) 0.4 J 21. The watt second is a unit of A) power B) energy C) potential difference D) electric field strength 22. Two elevators, A and B, move at constant speed. Elevator B moves with twice the speed of elevator A. Elevator B weighs twice as much as elevator A. Compared to the power needed to lift elevator A, the power needed to lift elevator B is A) the same B) twice as great C) half as great D) four times as great 23. What is the maximum height to which a motor having a power rating of 20.4 watts can lift a 5.00-kilogram stone vertically in 10.0 seconds? A) m B) m C) 4.16 m D) 40.8 m 24. A pendulum is made from a 7.50-kilogram mass attached to a rope connected to the ceiling of a gymnasium. The mass is pushed to the side until it is at position A, 1.5 meters higher than its equilibrium position. After it is released from rest at position A, the pendulum moves freely back and forth between positions A and B, as shown in the diagram below. What is the total amount of kinetic energy that the mass has as it swings freely through its equilibrium position? [Neglect friction.] A) 11 J B) 94 J C) 110 J D) 920 J 25. A car uses its brakes to stop on a level road. During this process, there must be a conversion of kinetic energy into A) light energy B) nuclear energy C) gravitational potential energy D) internal energy

4 Base your answers to questions 26 through 29 on the information below. A runner accelerates uniformly from rest to a speed of 8.00 meters per second. The kinetic energy of the runner was determined at 2.00-meter-per-second intervals and recorded in the data table below. 26. Plot the data points for kinetic energy of the runner versus his speed. 27. Draw the line or curve of best fit. 28. Calculate the mass of the runner. [Show all work, including the equation and substitution with units.] 29. A soccer player having less mass than the runner also accelerates uniformly from rest to a speed of 8.00 meters per second. Compare the kinetic energy of the less massive soccer player to the kinetic energy of the more massive runner when both are traveling at the same speed.

5 Base your answers to questions 30 and 31 on the information below. A student produced various elongations of a spring by applying a series of forces to the spring. The graph below represents the relationship between the applied force and the elongation of the spring. 30. Determine the spring constant of the spring. 31. Calculate the energy stored in the spring when the elongation is 0.30 meter. [Show all work, including the equation and substitution with units.] 32. Calculate the time required for a newton net force to stop a kilogram car initially traveling at 10. meters per second. [Show all work, including the equation and substitution with units.]

6 Answer Key 2013 midterm + 2nd quarter exam 1. A 2. C 3. B 4. D 5. C 6. B 7. A 8. D 9. A 10. A 11. C 12. B 13. A 14. D 15. D 16. Fg = N 17. B 18. B 19. C 20. C 21. B 22. D 23. C 24. C 25. D kg 29. The less massive soccer player has less kinetic energy N/m 31. PEs = 0.90 J 32. t = 2.0 s