Question

Two balls a and b of masses 40 g and 50g are moving with the velocity of 40m/s and 30 m/s if after colliding ball b moves with the velocity of 25 m/s. calculate the velocity of ball a

Answer 1

Mass of ball A, m 1=40g

Mass of ball B, m 2 =50g

Initial velocity of ball A, u 1 =40m/s

Initial velocity of ball B, u 2 =30m/s

Final velocity of ball A, v v =?=v

Final velocity of ball B, v

2

=25m/s

According to the law of conservation of momentum

m

1

u

1

+m

2

u

2

=m

1

v

1

+m

2

v

2

40×40+50×30=40×v+50×25

1600+1500=40v+1250

3100−1250=40v

1850=40v

v=

40

1850

v=46.45m/s

Hence, Final velocity of ball A, v

1

=v=46.25m/s