Question

A car 'A' of mass 1500 kg, travelling at 25m/s collides with another car 'B' of mass 1000kg travelling at 15m/s in the same direction. after collision, velocity of car 'A' becomes 20 m/s. Find velocity of car 'B' after collision?

Answer 1

Car A : 
m [mass]=1500 kg
u [initial velocity]=15 m/s
After collision: 
According to law of conservation of momentum 
total momentum before collision = Total momentum after collision
the velocity after collision =22.5 m/s