Question

Two balls, each with a mass of 0.5 kg, collide on a pool table. Is the law of conservation of momentum satisfied in this collision? Explain why or why not.

Answer 1

Conservation of momentum is a fundamental law of physics. This law states that the momentum of a system is constant if there are no external forces acting on the system. In a situation in which two balls, each with a mass of 0.5 kg, collide on a pool table the law of conservation of momentum is not satisfied because there are external forces that moved the balls. 

Answer 2

Yes, the law of conservation of momentum is satisfied. The total momentum before the collision is 1.5 kg • m/s, and the total momentum after the collision is 
1.5 kg • m/s. The momentum stays the same after the collision.