Atennis ball is dropped from 1.97 m above the
ground. it rebounds to a height of 0.945 m.
with what velocity does it hit the ground?
the acceleration of gravity is 9.8 m/s? . (let
down be negative.)
answer in units of m/s.

The ball hits the ground with velocity 6.21 m/s downward

Explanation:

A tennis ball is dropped from 1.97 m above the  ground

It rebounds to a height of 0.945 m

We need to find its velocity when it hits the ground

The acceleration of gravity is 9.8 m/s

The given is:

→ Initial velocity = 0 m/s

→ Height = 1.97 meters

→ Acceleration = 9.8 m/s²

→ v = ?

We need a rule satisfies the given

→ v² = u² + 2 a h

where u is the initial velocity, v is the final velocity, a is the acceleration

and h is the height

Substitute the values above in the rule

→ v² = (0)² + 2(9.8)(1.97)

→ v² = 38.612

Take √ for both sides

→ v = ±

→ v = - 6.21

We put negative sign for the value of velocity because it's downward

The ball hits the ground with velocity 6.21 m/s downward

the answer is 46 mls because when you add the speed per second it increses the speed