Angular momentum of rigid bodies,When to add (moment of inertia*angular velociy)

1. tj00343

45
The rigid 30-lb plank is struck by the 15-lb hammer
head H. Just before the impact the hammer is gripped
loosely and has a vertical velocity of 75 ft>s. If the coefficient
of restitution between the hammer head and the plank is
e = 0.5, determine the maximum height attained by the 50-lb
block D. The block can slide freely along the two vertical
guide rods. The plank is initially in a horizontal position.