If a catapault throws a tennis ball at an intial velocity of 13 m/s, at what angle will it need to throw the ball to hit a target 40 ft away?

Answer 1

First of all, convert to meters. 40 m = 12.19 m

The time of flight T must be such that
12.19 m = 13 m/s cos A * T

T also must satisfy (from the vertical equation of motion)

(T/2) g = 13 m/s * sin A

If you divide one equation by the other you can get an equation for tan A and eliminate the T unkonown.

Answer 2

I am still lost...a little more help please!