Question

57.0- g tennis ball is traveling straight at a player at 21.0 m/ s. The player volleys the ball straight back at 25.0 m/ s. If the ball remains in contact with the racket for 0.060 0 s, what average force acts on the ball?

Answer 1

Answer:43.7 N

Explanation:

Given

Mass of tennis ball is =57 gm

velocity of ball=21 m/s

The player volleys the ball straight back at 25 m/s(i.e. in opposite of initial direction)

time of contact=0.06 s

We know change in momentum$(\Delta P) =Impulse(Fdt)$

initial momentum$=57\times 10^{-3}\times 21$

final momentum$=-57\times 10^{-3}\times 25$

change in momentum

$\Delta P=57\times 10^{-3}\times 21-(-57\times 10^{-3}\times 25)$

$\Delta P=57\times 10^{-3}\times 46=2.622 kg-m/s$

Now 2.622$=F_{avg}\times 0.06$

$F_{avg}=43.7 N$