Answer to Question #103414 in Mechanics | Relativity for Bryan Torres

Question

A projectile's launch speed is 6.70 times its speed at maximum height. Find the launch angle θ0.

Answer 1

The velocity of the projectile at maximum height

$$v=v_0\cos\theta.$$

Hence

$$v_0=6.70v=6.70v_0\cos\theta.$$ $$\cos\theta=1/6.70=0.149,$$

$$\theta=81.4^{\circ}$$