Two billiard balls A and B, each of mass 50 kg and moving in oppsite direction with speed of `5ms^-1` each, collide and rebound with the same speed. If the collision lasts for `10^-3s`, which of the follwing statements are true?

Options

A. The impulse imparted to each ball is `0.25 kg s^-1` and the force on each ball is 250N
B. the impulse imparted to each ball is `0.25 kg s^-1` and the force exerted on each ball is `25 times 10^-5 N`
C. The impulse imparted to each ball is 0.5 Ns
D. The impulse and the force on each ball are different in magnitude and acts in same direction.

Answer

C

Explanation

`m_a=m_B=50g=50g times 10^-3 kg`
`v_a=-v_B=5ms^-1`
Impulse imparted to each ball on collision
=change in momentum of each ball
`=2m_Av_A=2m_Bv_B`
`=2 times 50 times 10^-3 times 5=0.5 Ns`
Force `=(Impu lse)/(time)= (chang e i n momentum)/10^-3`
`=0.5/10^-3=500N`
As direction of change of momentum of A is opposite to that of B, so the impulse and force on each ball are equal in magnitude and opposite in direction