A projectile is fired at an upward angle of 55.0 degrees from the top of a 230m cliff with a speed of 180m/s.What will be its speed when it strikes the ground below? (Use conservation of energy.)

Answer 1

You won't need to use the angle information.

What don't you understand about using conservation of energy?

Set the loss of potential energy (M g H) equal to the INCREASE in kinetic energy (1/2) M V^2. The mass will cancel out, so you don't need to know it.

Vf^2 - Vi^2 = 2 g H

H = 230 m and Vi = 180 m/s

Compute the final velocity Vf