Question

A ball was kicked upward at a speed of 64.2 m/s. How fast was the ball going 1.5 seconds later

Answer 1

The ball's velocity
`v` at time
`t` is

`v=v_0-gt`

where
`g=9.81\,(\mathrm m)/(\mathrm s^2)` is the acceleration due to gravity. So after 1.5 seconds, the ball's velocity is

`v=64.2\,(\mathrm m)/(\mathrm s)-\left(9.81\,(\mathrm m)/(\mathrm s^2)\right)(1.5\,\mathrm s)`

`\implies v=49.5\,(\mathrm m)/(\mathrm s)`

so the ball's speed after 1.5 seconds is also 49.5 m/s.