# 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??

Let's consider the equation of speed $v = v - a t$ for the vertical component.
So $v - a t = 0$ and $t = \frac{v}{g}$. 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.