Velocity is the rate of change of distance over time.
The ball's approximate vertical speed when it hits the ground is 19.8m/s
The maximum height of an object, thrown up is calculated as:
[tex]\mathbf{h_{max} = \frac{v^2}{2g}}[/tex]
Where:
[tex]\mathbf{h_{max} = 20m}[/tex] --- the maximum height
[tex]\mathbf{v = ??}[/tex] --- final velocity
[tex]\mathbf{g = 9.8ms^{-2}}[/tex] --- acceleration due to gravity
So, we have:
[tex]\mathbf{h_{max} = \frac{v^2}{2g}}[/tex]
[tex]\mathbf{20 = \frac{v^2}{2 \times 9.8}}[/tex]
Solve for v^2
[tex]\mathbf{v^2 = 2 \times 9.8 \times 20}[/tex]
[tex]\mathbf{v^2 = 392}[/tex]
Take square roots of both sides
[tex]\mathbf{v = 19.8ms^{-1}}[/tex]
Hence, the ball's approximate vertical speed when it hits the ground is 19.8m/s
Read more about velocity at:
https://brainly.com/question/13639113
