A ball is thrown straight up at 20 m. What is the balls velocity as it hits the ground?

The velocity of the ball as it hit the ground = 19.799 m/s

Explanation:

Velocity: Velocity of a body can be defined as the rate of change of displacement of the body. The S. I unit of velocity is m/s. velocity is expressed in one of newtons equation of motion, and is given below.

v² = u² + 2gs ... Equation 1

Where v = the final velocity of the ball, g = acceleration due to gravity, s = the height of the ball

Given: s = 20 m, u = 0 m/s

Constant: g = 9.8 m/s²

Substituting these values into equation 1,

v² = 0 + 2*9.8*20

v² = 392

v = √392

v = 19.799 m/s.

Therefore the velocity of the ball as it hit the ground = 19.799 m/s