Question

(a) With what speed must a ball be thrown vertically from ground level to rise to a maximum height of ? (b) How long will it be in the air ?

Answer 1

`t_f=2*v_i/g " flying time"`
`h_max=(v_i^2)/(2*g)`

Explanation:

`v_f=v_i-g*t`
`v_f=0 " if object reaches to maximum height"`
`v_i=g*t`
`t=v_i/g " elapsed time to reach of maximum height"`
`t_f=2*v_i/g " flying time"`
`v_i^2=2*g*h_max`
`h_max=(v_i^2)/(2*g)`