Question

If a projectile is shot at an angle of `pi/4` and at a velocity of `15 m/s`, when will it reach its maximum height??

Answer 1

The projectile will reach its maximum height at 1.08 s

Explanation:

This is the classical parabolas motion problem.
Let's consider the equation of speed `v=v-at` for the vertical component.
When the projectile will reach its maximum the vertical component will be 0.
So `v-at=0` and `t=v/g`. Obviously we consider the vertical component of speed `v=vsin45°` and use this value in the last formula. We find `t=(vsin45°)/g=1.08s`.
That's all.