7. An 8 kg ball is travelling to the east at 10 ms', collides with a 2 kg ball travelling to the west with a velocity of 5 ms'. After the collision, they move together. Determine the
final velocity of the balls. Assume that there are no resistive forces.

The final velocity of the ball is 7m/s

Explanation:

M1=8kg,  V1 =10m/s , M2=2kg , V2=-5m/s

initial momentum before collison

m1v1+m2v2

=8×10 +2×(-5)  =80-10  = 70kg m/s

final momentum after collison

=(m1+m2)×v

=(8+2)×v

=10v

According to the law of conversion of momentum

initial momentum =final momentum

70=10v

10v=70

v=70/10

v=7m/s

answer(20) psi;