Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

A 0.262-kg volleyball approaches a player horizontally with a speed of 17.9 m/s.

ID: 1568044 • Letter: A

Question

A 0.262-kg volleyball approaches a player horizontally with a speed of 17.9 m/s. The player strikes the ball with her fist and causes the ball to move in the opposite direction with a speed of 21.5 m/s. (a) What impulse is delivered to the ball by the player? (Take the direction of final velocity to be the positive direction. Indicate the direction with the sign of your answer.) _______ kg middot m/s (b) If the player's fist is in contact with the ball for 0.0600 s, find the magnitude of the average force exerted on the player's fist. _________ N High-speed stroboscopic photographs show that the head of a 280-g golf club is traveling at 54 m/s just before it strikes a 46-g golf ball at rest on a tee. After the collision, the club head travels (in the same direction) at 40 m/s. Find the speed of the golf ball just after impact. __________ m/s

Explanation / Answer

5) m = 0.262 kg , u1 = -17.9 m/s

v = 21.5 m/s

(A) impulse = change in momentum

= m(v-u)

= 0.262(21.5 +17.9)

= 10.3 kg.m/s

(B) Force = impulse/time

F = 10.3/0.06

F = 172 N


6) m1 = 280 g , u1 = 54 m/s

m2 = 46 g , u2 =0

v1 = 40 m/s

from conservaiton of momentum

m1u1 + m2u2 = m1v1 +m2v2

280*54+0 = 280*40+46*v2

v2 = 85.2 m/s