Answer: F = 1511.11N
Explanation: Given that
Mass M = 0.17 kg
Distance S = 9cm = 0.09 m
Initial velocity U = 40 m/s
Final velocity V = 0
V = 0 since the ball is coming to rest. So acceleration will be negative because the ball is actually decelerating.
Using 2nd equation of motion,
V^2 = U^2 - 2aS
0 = 40^2 - 2×a×0.09
0 = 1600 - 0.18a
1600 = 0.18a
a = 1600/0.18
a = 8888.89
The average force applied F = Ma
F = 0.17 × 8888.89
F = 1511.11N