A ball is dropped from a height h and falls the last half of its distance in 4 seconds. How long does the ball fall? From what height is the ball originally dropped?

How long does the ball fall is t_2 =  13.66 (s).

From what height is the ball originally dropped is h=  913.90 (m).

Explanation:

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.