Question

A basketball is tossed up into the air, falls freely, and bounces from the wooden floor. From the moment after the player releases it until the ball reaches the top of its bounce, what is the smallest system for which momentum is conserved?'

Answer 1

The smallest system in which momentum is conserved for a basketball tossed and bounced off a floor includes both the basketball and the Earth. The total momentum of this basketball-Earth system remains constant, adhering to the principle of conservation of momentum.

Step-by-step explanation:

When considering the smallest system for which momentum is conserved involving a basketball tossed into the air, falls freely and bounces off a wooden floor, we must take into account not only the basketball but also the Earth. This is because the forces involved in the basketball's motion (gravity pulling it down, the floor pushing it up) are exerted by the Earth. Therefore, the smallest system in which momentum is conserved after the basketball is released until the top of its bounce is the basketball-Earth system. During this interaction, the total momentum of this system remains constant, as any change in momentum of the basketball is balanced by an equal and opposite change in the momentum of the Earth, even though the Earth's change in motion is imperceptible due to its vastly greater mass.

To illustrate the conservation of momentum further, consider the analogy with a football player and goalpost. Just as Earth recoils slightly when a player collides with a goalpost, the Earth also recoils in response to the bouncing basketball. It's important to note that the Earth's change in velocity is negligible, but it ensures that the law of conservation of momentum holds true for the closed system consisting of the basketball and the planet.

Answer 2

Tha ball- earth/floor system.

Step-by-step explanation:

The force acting on the ball is the force of gravity when ignoring air resistance. At the moment the player releases the ball, until it reaches the top of its bounce, the small system for which the momentum is conserved is the ball- floor system. The balls exerts and equal and opposite force on the floor. Here the ball hits the floor, because in any collision the momentum is conserved. Moment of the ball -floor system is conserved. Mutual gravitation bring the ball and floor together in one system. As the ball moves downwards, the earth moves upwards, although with an acceleration on the order of 1025 times smaller than that of the ball. The two objects meet, rebound and separate.