A truck of mass 500 kg moving at 4 m/s collides with another truck of mass 1500 kg moving in the same direction at 2 m/s. What is their common velocity just after the collision if they move off together?
Let
m1=500,
m2=1500
u1=4m/s
u2=2m/s
v1=v2 (since after collision they stuck together)
According to law of conservation of momentum,
m1u1 + m2u2 = m1v1 + m2v2
500 x 4 + 1500 x 2 = (500 + 1500) v
5000 = 2000v
v = 5000/2000
v = 2.5m/s