What Is the Launch Angle of a Ball Thrown Against a Wall?

[richpetty888]

Homework Statement

A ball is thrown with initial velocity 20m/sec against a wall 50 meters away. It is released from a height of 1.8 meters, and hits the wall at 1.2 meters. Find the angle of the throw.

Homework Equations

50=20t*cos(theta)
-.6=20t*sin(theta)-.5(9.8)(t^2)

The Attempt at a Solution

Is it possible to solve this problem without knowing t(time between launch and hitting the wall)? Thanks for the help, I need to know if I'm missing a formula or something.

 

[Pheo1986]

im not 100% sure about this but you don't need to find t, you just need to rearange your 1st equatoin so you have t=... and then substitute that into your 2nd equation and then you can find theta. maybe