Question

A ball of mass 100 g moving with velocity of 10 m/s is stooped by a boy in 0.2 seconds. Calculate the force applied by the boy.

Answer 1

mass, m=100g
initial velocity, u=10m/s
final velocity, v=0m/s (as ball comes to rest)
time, t=0.2s

Acceleration, a=v-u/t
a=10-0/0.2
a=10/2/10
a=100/2
a=50m/s∧2

force, f =m*a
f=100*50
f=5000N

Answer 2

mass, m=100g

initial velocity, u=10m/s

final velocity, v=0m/s (as ball comes to rest)

time, t=0.2s

Acceleration, a=v-u/t

a=10-0/0.2

a=10/2/10

a=100/2

a=50m/s∧2

force, f =m*a

f=100*50

f=5000N