Answer:
B. 60 N
Step-by-step explanation:
Change in momentum after ball bounces back = m ( v - u )
v is velocity after the bounce and u is before the bounce
= .15 ( 6.5 + 3.5 )
1.5 kg m /s
If F be the average force acting on the ball which changed its velocity
impulse of force = force x time
= F x .025
Impulse of force = change in momentum
F x .025 = 1.5
F = 1.5 / .025
= 60 N .