Problem 2.

A child throws a ball downward from a tall building. Note that the ball is thrown, not dropped and disregard air resistance. What is the acceleration of the ball immediately after it leaves the child's hand?

Solution:

After the ball leaves the child's hand it is in the air.

There is only one force acting on the ball in the air (if we disregard air resistance).

This force is the gravitational force.

This force will provide acceleration – free fall acceleration.

Therefore the acceleration of the ball is the free fall acceleration: