p10_083.pdf

83. (a) The impulse on the ball is

J =∆ p = mv

−

0=(46

10 − 3 kg)(50m / s)i=(2 . 3N

s)i

where we choose i to be in the direction of the velocity v of the ball as it leaves the club (at 30 ◦

above horizontal – so it is like the x axis of an inclined plane problem).

(b) The impulse on the club is, by Newton’s third law, J =

−

J =

−

(2 . 3N

s)i. We note that it is

directed opposite to the direction of motion.

F avg =

∆ t =

1 . 7 × 10 − 3 = 1400 ˆ iN .

(2 . 3)i

(d) The work done on the ball is

W =∆ K = 1

2 mv 2 = 1

2 (46

10 − 3 )(50) 2 =58J .