Question

A yellow train of mass 100 kg is moving at 8 m/s toward an orange train of mass 200 kg traveling in the opposite direction on the same track at a speed of 1 m/s. They collide and stick together! What is the final momentum of the new combined train?

A. 100 kgm/s
B. 600 kgm/s
C. 800 kgm/s
D. 80 kgm/s

Answer 1

Let the momentum of the orange train be positive

P = 100 * 8 - 200 * 1 = 600 kg-m/s

P(final) = 600 kg-m/s

P / M = 600 kg-m/sec / 300 kg = 2 m/s

Answer-B final momentum = 600 kg-m/s