Homework Part 1 - Conceptual Understanding of Momentum CHANGES IN ENERGY AND MOMENTUM Name 1. Ball A leaves the edge of a level table with speed VA, and falls to the floor. At the instant ball A leaves the table edge, another identical ball, B, is released from rest at the height of the table top and also falls to the floor. It is observed that the balls reach the floor at the same time. a. In each question below, consider the interval that begins when the balls begin falling and ends just before they reach the floor. 78 = 0 i. Is the magnitude of the impulse imparted to ball B greater than, less than, or equal to the magnitude of the impulse imparted to ball A? Explain your reasoning. ii. In the spaces provided at right, draw an arrow to indicate the direction of the impulse imparted to each ball. Explain your reasoning. Direction of the impulse imparted to Ball A Ball B iii. Is the work done on ball B greater than, less than, or equal to the work done on ball A? Explain your reasoning. b. In each question below, consider the balls just before they reach the floor. i. Is the magnitude of the momentum of ball B greater than, less than, or equal to the magnitude of the momentum of ball A? Explain your reasoning. ii. Is the kinetic energy of ball B greater than, less than, or equal to the kinetic energy of ball A? Explain your reasoning. Tutorials in Introductory Physics McDermott, Shaffer, & P.E.G., U. Wash. Prentice Hall, Inc. First Edition, 2002 Mech HW-53 Mech Changes in energy and momentum HW-54 2. Two identical pucks slide across a level, frictionless table. Initially, the pucks have the same speed, but their velocities are perpendicular to each other as shown. The same constant force is exerted on each puck for the same interval of time: from the instant shown until puck 1 crosses the second dotted line. The pucks remain on the table and do not collide during this time interval. 021 a. When puck 1 crosses the second dotted line, is puck 2 to the left of, to the right of, or crossing the second dotted line? Explain how you can tell. In the diagram above, sketch the trajectory of each of the pucks. Explain how you decided to draw the trajectories the way you did. b. When puck 1 crosses the second dotted line, is the magnitude of its momentum greater than, less than, or equal to the magnitude of the momentum of puck 2 at the same instant? Explain the reasoning you used in making this comparison. c. When puck 1 crosses the second dotted line, is the kinetic energy of puck 1 greater than, less than, or equal to the kinetic energy of puck 2 at the same instant? Explain the reasoning you used in making this comparison. Tutorials in Introductory Physics Prentice Hall, Inc. McDermott, Shaffer, & P.E.G., U. Wash. First Edition, 2002

Homework Part 1 - Conceptual Understanding of Momentum CHANGES IN ENERGY AND MOMENTUM Name 1. Ball A leaves the edge of a level table with speed VA, and falls to the floor. At the instant ball A leaves the table edge, another identical ball, B, is released from rest at the height of the table top and also falls to the floor. It is observed that the balls reach the floor at the same time. a. In each question below, consider the interval that begins when the balls begin falling and ends just before they reach the floor. 78 = 0 i. Is the magnitude of the impulse imparted to ball B greater than, less than, or equal to the magnitude of the impulse imparted to ball A? Explain your reasoning. ii. In the spaces provided at right, draw an arrow to indicate the direction of the impulse imparted to each ball. Explain your reasoning. Direction of the impulse imparted to Ball A Ball B iii. Is the work done on ball B greater than, less than, or equal to the work done on ball A? Explain your reasoning. b. In each question below, consider the balls just before they reach the floor. i. Is the magnitude of the momentum of ball B greater than, less than, or equal to the magnitude of the momentum of ball A? Explain your reasoning. ii. Is the kinetic energy of ball B greater than, less than, or equal to the kinetic energy of ball A? Explain your reasoning. Tutorials in Introductory Physics McDermott, Shaffer, & P.E.G., U. Wash. Prentice Hall, Inc. First Edition, 2002 Mech HW-53 Mech Changes in energy and momentum HW-54 2. Two identical pucks slide across a level, frictionless table. Initially, the pucks have the same speed, but their velocities are perpendicular to each other as shown. The same constant force is exerted on each puck for the same interval of time: from the instant shown until puck 1 crosses the second dotted line. The pucks remain on the table and do not collide during this time interval. 021 a. When puck 1 crosses the second dotted line, is puck 2 to the left of, to the right of, or crossing the second dotted line? Explain how you can tell. In the diagram above, sketch the trajectory of each of the pucks. Explain how you decided to draw the trajectories the way you did. b. When puck 1 crosses the second dotted line, is the magnitude of its momentum greater than, less than, or equal to the magnitude of the momentum of puck 2 at the same instant? Explain the reasoning you used in making this comparison. c. When puck 1 crosses the second dotted line, is the kinetic energy of puck 1 greater than, less than, or equal to the kinetic energy of puck 2 at the same instant? Explain the reasoning you used in making this comparison. Tutorials in Introductory Physics Prentice Hall, Inc. McDermott, Shaffer, & P.E.G., U. Wash. First Edition, 2002