The engine of an unpowered toy train is rolling at a constant speed on a level track. the engine collides with a stationary toy truck and joins with it. before the collision, the toy engine is travelling at 0.32 m/s. the mass of the engine is 0.50 kg.
(a) calculate the momentum of the toy engine before the collision.
(b) the mass of the truck is 0.30 kg.​