Homework # 31 - Conservation of Momentum Problems Handout Problems: 1. A 3.0-kilogram mass changes speed from 5.0 meters per second to 20 meters per second. What is the change in the object's momentum? 2. A 0.050-kg bullet is fired from a 4.0-kg rifle that is initially at rest. If the bullet leaves the rifle with momentum having a magnitude of 20. kg.m/s, what will the magnitude of the momentum that the rifle recoils with be? 3. A toy railroad engine having a mass of 1.5 kg and moving on a straight track at 0.20 m/s collides with a similar engine ahead of it moving in the same direction at 0.12 m/s. On colliding, the engines lock and remain together. (a) What is the momentum of each engine before the collision? (b) What is the magnitude and direction of the momentum of both engines after the collision? (c) What is the velocity of the pair of engines after the collision? 4. When a car of mass 2.0 x 103 kg moving at 9.0 m/s collides head on with a second car having a mass of 1.5 x 103 kg, the cars lock and come to rest at the point of collision. What was the velocity of the second car before the collision? 5. A 1-kg body moving forward at 5 m/s hits a second body at rest. After the collision, the 1-kg body reverses its direction and moves at 1 m/s while the second body moves forward at 2 m/s. What is the mass of the second body