Question

Twoballs A and B of masses 40 g and 50 g are moving at speed of 40 m/s and 30 m/s respectively. if after colliding , B stars moving with a velocity of 25 m/s, what is the velocity of A?​

Answer 1

Explanation:

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 1 =?=v

Final velocity of ball B, v 2 =25m/s

According to the law of conservation of momentum

m1 uu +m2 uu =m1 v1 +m2v2 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