Lecture 17 Discussion (Linear Momentum and Collisions)

[1] An estimated force–time curve for a baseball struck by a bat is shown in Figure. From this curve, determine

(a) the impulse delivered to the ball, (b) the average force exerted on the ball, and (c) the peak force exerted on the ball.

[2] Two blocks are free to slide along the frictionless wooden track ABC shown in Figure. The block of mass m1 = 5.00 kg is released from A. and makes a head on elastic collision with a block of mass m2 =10.0 kg, initially at rest at point B. Calculate the maximum height to which m1 rises after the elastic collision..

[4]As shown in Figure , a bullet of mass m and speed v passes completely through a pendulum bob of mass M. The bullet emerges with a speed of v/2. The pendulum bob is suspended by a stiff rod of length L and negligible mass. What is the minimum value of v such that the pendulum bob will barely swing through a complete vertical circle?

[5] Two blocks of masses M and 3M are placed on a horizontal, frictionless surface. A light spring is attached to one of them, and the blocks are pushed together with the spring between them (Fig.). A cord initially holding the blocks together is burned; after this, the block of mass 3M moves to the right with a speed of 2.00 m/s. (a) What is the speed of the block of mass M? (b) Find the original elastic potential energy in the spring if M = 0.350 kg.

[6] Show that the center of mass of a rod of mass M and length L lies in midway between its ends, assuming the rod has a uniform mass per unit length.