A student bounces a tennis ball. She drops the ball, and then it bounces back up to her. When does the ball have zero kinetic energy?(1 point)
Responses
Just after it hits the ground
Just after it hits the ground
At the very top of its bounce
At the very top of its bounce
Exactly when it hits the ground
Exactly when it hits the ground
As soon as she drops it
Just after it hits the ground
The ball has zero kinetic energy exactly when it hits the ground.
The ball has zero kinetic energy at the very top of its bounce. To understand why, let's break down the concept of kinetic energy. Kinetic energy is the energy possessed by an object due to its motion. It depends on both the mass and the velocity of the object.
When the student drops the ball, it starts to gain speed as it falls towards the ground. As it moves closer to the ground, its velocity increases, and so does its kinetic energy. Just before it hits the ground, the ball has its maximum kinetic energy.
However, when the ball reaches the very top of its bounce, it momentarily comes to a stop before changing direction and falling back down. At this point, the ball's velocity is zero, meaning it has no motion. Since kinetic energy depends on velocity, when the velocity is zero, the kinetic energy is also zero.
Therefore, the answer to the question is that the ball has zero kinetic energy at the very top of its bounce.