Answer:
Step-by-step explanation:
mass of ball, m = 0.530 kg 
initial sped, u = 18 m/s 
final speed, v = - 13.5 m/s 
time, t = 0.1 s 
(a) Impulse is defined as the change in momentum. 
I = change in momentum 
I = m ( v - u) 
I = 0.530 x ( - 13.5 - 18) 
I = 16.7 N s 
(b) Force is defined as the rate of change of momentum. 
F = m ( v - u) / t 
F = 16.7 / 0.1 = 167 N