Consider the motion of the two projectiles fired at t = 0. Their initial speeds are both v0 but they are fired with different initial angles θ1 and θ2 with respect to the horizontal.

Question

What is the ratio of the times of the flights?

Answer 1

flight time is determined by the vertical component of velocity

Tf = 2[v0 sin(Θ)] / g

so the ratio of the flight times is the ratio of the sines of the launch angles