Question

From a lengthof 31m a ball dropped on a horizontal ground rebound with half

of its velocity with which it hits the ground

What is the velocity with which it hits the ground?

What is the time interval between the first and thesecond impacts of the ball

with the ground?

Answer 1

The velocity is

$$v=\sqrt{2gh}=24.6\text{ m/s}.$$

The time:

$$t=v/g=2.5\text{ s}.$$