Homework: Momentum 1. Two blocks are on a frictionless, level track. Block B has more mass than block A. Initially, block B is moving toward block A, which is at rest. After the collision, the blocks stick together. i. At the instant of collision, how does the net force on block A compare with the net force on block B? Discuss both magnitude and direction. Name Emma Morales Section Before A B After A B Force is exerted by block A or block B is toward the right Force exerted by Block B to block A is towards the Reft ii. For any given time interval At during the collision, how does the impulse on block A compare with the impulse on block B? Discuss both magnitude and direction. iii. Draw arrows to represent the change in velocity vector for block A and block B for the collision. Change in velocity for block A Change in velocity for block B iv. Draw vectors to show the change in momentum vector for each block over the same small interval. Is the magnitude of the change in momentum of block A greater than, less than, or equal to the magnitude of the change in momentum of block B? v. Is the magnitude of the change in velocity for block A greater than, less than, or equal to the magnitude of the change in velocity for block B? Explain. vi. Calculate the final velocity for both blocks if initial velocity of block B is 6 m/s, the mass of block B is 0.6kg, and the mass of block A is 0.3 kg. vii. Calculate the final velocity for both blocks if initial velocity of block B is 6 m/s, m= mB= 300 g. Copyright 2008 by S. Kanim, M.Loverude, & L.Gomez 3. 2. Lab Homework: Momentum Two blocks, C and D are pushed toward one another on a frictionless surface as shown. Block C has a mass of 3 kg and block D has a mass of 5 kg. i. Find the initial momentum (magnitude and direction) of block C. ii. Find the initial momentum (magnitude and direction) of block D. = 8 m/s VD = 4 m/s C iii. Find the initial momentum (magnitude and direction) of the system consisting of blocks C and D. Suppose that after blocks C and D from problem 2 collided, they stuck together. Find the final velocity (magnitude and direction) for the two blocks. Show how you determined your answer. 4. Suppose that after blocks C and D from problem 2 collided, block C remained at rest. Find the final velocity (magnitude and direction) for block D. Show how you determined your answer. 5. Suppose that after blocks C and D from problem 2 collided, block C moved off to the left with a speed of 2 m/s. Find the final velocity (magnitude and direction) for block D. Show how you determined your answer. 6. In problems 3 - 5, we looked at 3 different possible results of the collision between the two blocks. If we were to set up the experiment shown in problem 2, what property of the blocks will determine what will actually happen after the collision? Copyright 2008 by S. Kanim, M.Loverude, & L.Gomez 2