The momentum of an object is defined as the object's a. mass times its velocity. b. force times the time interval. c. force times its acceleration. d. mass times it acceleration. e. velocity times the time interval. The momentum of an object is defined as the object's a. mass times its velocity. b. force times the time interval. c. force times its acceleration. d. mass times it acceleration. e. velocity times the time interval. Which has more momentum, a large truck moving at 30 miles per hour or a small truck moving at 30 miles per hour? a. Both have the same momentum. b. The small truck c. The large truck Which has more momentum, a large truck moving at 30 miles per hour or a small truck moving at 30 miles per hour? a. Both have the same momentum. b. The small truck c. The large truck Compared to a sports car moving at 30 miles per hour, the same sports car moving at miles per hour has a. twice as much momentum. b. four times as much momentum. c. the same momentum. Compared to a sports car moving at 30 miles per hour, the same sports car moving at miles per hour has a. twice as much momentum. b. four times as much momentum. c. the same momentum. A 2-kg ball is thrown at 3 m/s. What is the ball's momentum? a. b. c. d. e. 2 kg·m/s 3 kg·m/s 6 kg·m/s 9 kg·m/s none of the above A 2-kg ball is thrown at 3 m/s. What is the ball's momentum? a. b. c. d. e. 2 kg·m/s 3 kg·m/s 6 kg·m/s 9 kg·m/s none of the above The momentum change of an object is equal to the a. impulse acting on it. b. velocity change of the object. c. force acting on it. d. force acting on it times its velocity. e. object's mass times the force acting on it. The momentum change of an object is equal to the a. impulse acting on it. b. velocity change of the object. c. force acting on it. d. force acting on it times its velocity. e. object's mass times the force acting on it. In order to catch a ball, a baseball player moves his or her hand backward in the direction of the ball's motion. Doing this reduces the force of impact on the player's hand principally because a. the time of impact is decreased. b. the time of impact is increased. c. the velocity of the hand is reduced. d. the momentum of impact is reduced. e. none of the above In order to catch a ball, a baseball player moves his or her hand backward in the direction of the ball's motion. Doing this reduces the force of impact on the player's hand principally because a. the time of impact is decreased. b. the time of impact is increased. c. the velocity of the hand is reduced. d. the momentum of impact is reduced. e. none of the above Suppose a girl is standing on a pond where there is no friction between her feet and the ice. In order to get off the ice, she can a. bend over touching the ice in front of her and then bring her feet to her hands. b. walk very slowly on tiptoe. c. get on her hands and knees and crawl off the ice. d. throw something in the direction opposite to the way she wants to go. e. all of the above will work Suppose a girl is standing on a pond where there is no friction between her feet and the ice. In order to get off the ice, she can a. bend over touching the ice in front of her and then bring her feet to her hands. b. walk very slowly on tiptoe. c. get on her hands and knees and crawl off the ice. d. throw something in the direction opposite to the way she wants to go. e. all of the above will work A cannon recoils from launching a cannonball. The speed of the cannon's recoil is small because the a. impulse on the cannon is less than the impulse on the cannonball. b. cannon has far more mass than the cannonball. c. momentum of the cannon is unchanged. d. force against the cannon is relatively small. e. none of the above A cannon recoils from launching a cannonball. The speed of the cannon's recoil is small because the a. impulse on the cannon is less than the impulse on the cannonball. b. cannon has far more mass than the cannonball. c. momentum of the cannon is unchanged. d. force against the cannon is relatively small. e. none of the above In physics, work is defined as a. b. c. d. e. force times time. force divided by distance. distance divided by time. force divided by time. force times distance. In physics, work is defined as a. b. c. d. e. force times time. force divided by distance. distance divided by time. force divided by time. force times distance. If Nellie Newton pushes an object with twice the force for twice the distance, she does a. b. c. d. twice the work. the same work. four times the work. eight times the work. If Nellie Newton pushes an object with twice the force for twice the distance, she does a. b. c. d. twice the work. the same work. four times the work. eight times the work. Which requires more work: lifting a 70-kg sack vertically 2 meters or lifting a 35-kg sack vertically 4 meters? a. Lifting the 70 kg sack b. Lifting the 35 kg sack c. Both require the same amount of work. Which requires more work: lifting a 70-kg sack vertically 2 meters or lifting a 35-kg sack vertically 4 meters? a. Lifting the 70 kg sack b. Lifting the 35 kg sack c. Both require the same amount of work. Power is defined as the a. force on an object divided by the time the force acts. b. work done times the time taken to do that work. c. work done on an object divided by the time taken to do the work. d. distance divided by the time taken to move that distance. e. force on an object times the distance the object moves. Power is defined as the a. force on an object divided by the time the force acts. b. work done times the time taken to do that work. c. work done on an object divided by the time taken to do the work. d. distance divided by the time taken to move that distance. e. force on an object times the distance the object moves. A job is done slowly, and an identical job is done quickly. Both jobs require the same amount of work but different amounts of a. b. c. d. energy. power. both A and B none of the above A job is done slowly, and an identical job is done quickly. Both jobs require the same amount of work but different amounts of a. b. c. d. energy. power. both A and B none of the above Mechanical energy can be in the form of a. kinetic energy. b. potential energy. c. both kinetic and potential energy. d. neither kinetic nor potential energy. Mechanical energy can be in the form of a. kinetic energy. b. potential energy. c. both kinetic and potential energy. d. neither kinetic nor potential energy. The amount of potential energy possessed by an elevated object is equal to a. the power used to lift it. b. the distance it is lifted. c. the force needed to lift it. d. the work done in lifting it. e. the value of the acceleration due to gravity. The amount of potential energy possessed by an elevated object is equal to a. the power used to lift it. b. the distance it is lifted. c. the force needed to lift it. d. the work done in lifting it. e. the value of the acceleration due to gravity. An object at rest may have a. b. c. d. e. energy. speed. velocity. momentum. none of the above An object at rest may have a. b. c. d. e. energy. speed. velocity. momentum. none of the above When a car’s speed triples, its kinetic energy a. b. c. d. e. remains the same. triples. increases by four times. increases by nine times. none of the above When a car’s speed triples, its kinetic energy a. b. c. d. e. remains the same. triples. increases by four times. increases by nine times. none of the above An arrow in a bow has 70 J of potential energy. Assuming no loss of energy to heat, how much kinetic energy will it have after it has been shot? a. b. c. d. e. 0J 35 J 50 J 70 J 140 J An arrow in a bow has 70 J of potential energy. Assuming no loss of energy to heat, how much kinetic energy will it have after it has been shot? a. b. c. d. e. 0J 35 J 50 J 70 J 140 J A 40-kg football player leaps through the air to collide with and tackle a 50-kg player heading toward him, also in the air. If the 40-kg player is heading to the right at 9 m/s and the 50-kg player is heading toward the left at 2 m/s, what is the speed and direction of the tangled players? Discuss how energy is transformed form one form to another in a swinging pendulum. Where is potential energy the most? The least? Where is kinetic energy the most? The least? Where is it moving the fastest? Where is it stopped? Why does the pendulum eventually stop?