Question

If a projectile is shot at an angle of `pi/2` and at a velocity of `22 m/s`, when will it reach its maximum height??

Answer 1

I got: `2.2s`

Explanation:

If I interpreted it right, the bullet is shot perfectly vertically and will reach its maximum height where its final velocity `v_f` will be zero.
We can use kinematics in the form of the relationship:
`v_f=v_i+at`
where the acceleration `a` will be acceleration of gravity `g=9.8m/s^2` directed downwards (and so it will have a negative sign).
We get:
`0=22-9.8t`
rearranging:
`t=22/9.8=2.2s`