In the top row labeled Before Collision, the left billiard ball labeled 3 meters per second approaches the right billiard ball labeled 0 meters per second with a grey arrow pointing from the right ball to the left ball. In the bottom row labeled After Collision, the left billiard ball labeled 1 meters per second approaches the right billiard ball labeled 2 meters per second with grey arrows pointing to the right from both balls.

Question

In the top row labeled Before Collision, the left billiard ball labeled 3 meters per second approaches the right billiard ball labeled 0 meters per second with a grey arrow pointing from the right ball to the left ball. In the bottom row labeled After Collision, the left billiard ball labeled 1 meters per second approaches the right billiard ball labeled 2 meters per second with grey arrows pointing to the right from both balls.

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

To determine if the law of conservation of momentum is satisfied in this collision, we need to calculate the total momentum before the collision and compare it to the total momentum after the collision.

Before the collision:
Total momentum = (mass1 x velocity1) + (mass2 x velocity2)
Total momentum = (0.5 kg x 3 m/s) + (0.5 kg x 0 m/s)
Total momentum = 1.5 kg m/s + 0 kg m/s
Total momentum = 1.5 kg m/s

After the collision:
Total momentum = (mass1 x velocity1) + (mass2 x velocity2)
Total momentum = (0.5 kg x 1 m/s) + (0.5 kg x 2 m/s)
Total momentum = 0.5 kg m/s + 1 kg m/s
Total momentum = 1.5 kg m/s

Since the total momentum before the collision (1.5 kg m/s) is equal to the total momentum after the collision (1.5 kg m/s), we can conclude that the law of conservation of momentum is satisfied in this collision. This means that the total momentum of the system remains constant before and after the collision, demonstrating that momentum is conserved in this interaction.