A rock is thrown horizontally from the top of a 20-m high cliff and strikes the ground at an angle of 45 degrees. With what speed was it thrown?
R = V2/g*sin(2theta)
v2 = (v0*sin(theta))2 - 2gy
The Attempt at a Solution
I have 2 unknowns no matter what equation I try to use. I've tried to get it down to one unknown, but I keep getting the wrong answer..