1. During the fall:

* Gravitational acceleration (g): This is the constant acceleration due to gravity, acting downwards, approximately 9.8 m/s². This means the ball's downward velocity increases by 9.8 meters per second every second it falls.

2. During the bounce:

* Impact acceleration: When the ball hits the ground, it experiences a very rapid deceleration (negative acceleration) as it comes to a stop. This is followed by an equally rapid acceleration as it rebounds upward. This acceleration is much larger than gravitational acceleration and happens over a very short time.

* Elasticity: The material properties of the ball and the surface determine how much energy is lost during the bounce. A perfectly elastic bounce would conserve all the energy, leading to the same rebound speed as the impact speed. Real-world bounces involve some energy loss, leading to a slightly lower rebound speed.

3. During the rise:

* Gravitational deceleration: As the ball travels upwards, gravity acts against its motion, causing it to slow down. This is essentially negative acceleration (deceleration) due to gravity.

In summary:

A bouncing ball is constantly accelerating. It accelerates downwards due to gravity, decelerates rapidly during impact, accelerates upwards during rebound, and decelerates upwards again due to gravity. The key point is that acceleration is any change in velocity, and bouncing involves changes in both speed and direction.