Question

A baseball is hit straight up at an initial velocity of 100 m/s. How long will it take to hit the ground?

Answer 1

20 seconds

Explanation:

During upward motion
`v = u + at`
`0 = u + (-g t_1)`
`t_1 = u/g`

During downward motion
`v = u + at`
`u = 0 + g t_2`
`t_2 = u/g`

Total time `(T) = t_1 + t_2`

`T = (2u)/g = (2 × 100 ms^-1) / (10 ms^-2) = 20 color(white)(“)"seconds"`