At the top of its midair height, the ball is momentarily at rest, meaning its velocity is zero. However, the following forces are still acting on it:

* Gravity: This force constantly pulls the ball downwards towards the center of the Earth. It's the reason the ball eventually falls back down.

* Air Resistance: This force opposes the ball's motion and depends on factors like the ball's shape, speed, and the density of the air.

Important Note: While the ball's velocity is zero at the top, its acceleration is *not* zero. This is because gravity is still acting on the ball, causing it to accelerate downwards.