In: Physics
2) Momentum and Newton's Second Law: Impulse
(a) A block of wood is struck by a bullet. Is the block more likely to be knocked over if the bullet embeds itself in the wood or bounces back? Explain why. [Hint: in which case is the change in momentum of the bullet (and hence the force applied by the bullet) larger?]
(b) A sudden gust of wind exerts a force of 20.0 N for 1.20 s on a bird that had been flying at 5.00 m/s. As a result, the bird ends up moving in the opposite direction at 7.00 m/s. What is the mass of the bird?
(c) A 144-g baseball is moving toward home plate with a speed of 97mph when it is bunted (hit softly). The bat exerts an average force of 6.50 ×103 N on the ball for 1.30 ms (millisecond). The average force is directed toward the pitcher, which we take to be the positive x direction. What is the final speed of the ball?