Question

If a projectile is shot vertically from the ground at `1 m/s`, how long will it remain in the air?

Answer 1

`~~0.2s`

Explanation:

Since the projectile is projected vertically then free vertical motion under gravity to be applied.
Here Initial velocity `u = 1m/s`
If its time of flight be taken as T s, then after Ts it will return to the initial position at the ground ,making a verticalb displacement `h=0` Taking acceleration due to gravity `g =9.8ms^-2`
we can write:
`h=uxxT-1/2xxgxxT^2=>0=1xxT-1/2xx9.8xxT^2`
`:. T=1/4.9s~~0.2s`