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Collisions 16. Two balls A and B, having different but unknown masses, collide. A is initially at rest and B has a speed v. After collision, B has a speed v/2 and moves at right angles to its original motion. (a) Find the direction in which ball A moves after collision. (b) Can you determine the speed of A from the information given? Explain. 17. After a totally inelastic collision, two objects of the same mass and initial speed are found to move away together at half their initial speed. Find the angle between the initial velocities of the objects. 18. Two pendulums each of length L are initially situated as shown below. The first pendulum is released and strikes the second. Assume that the collision is completely inelastic and neglect the mass of the strings and any frictional effects. How high does the center of mass rise after the collision? mi Id