Question

A Van of mass 2000 kg. traveling at 40 m/s dashes into the rear of a bus of mass 10,000 kg. moving in the same direction at 5 m/s. The van bounces backward after the collision with a speed of 10 m/s. What was the velocity of the bus after the impact?

Answer 1

applying momentum balance
m1u1 + m2u2 = m1v1 + m2v2
2000*40 + 10000*5 = 2000*(-10) + 10000*v2
v2 = 15 in forward direction