A man stands on the roof of a 10.0 -tall building and throws a rock with a velocity of magnitude 30.0 at an angle of 38.0 above the horizontal. You can ignore air resistance.

Question

Calculate the horizontal distance from the base of the building to the point where the rock strikes the ground.

Answer 1

This problem was posted before, perhaps by you, since "10.0-" is still written instead of 10.0 meters. You need to say what the dimensions are.

As I said in my previous answer, the kinetic energy increase by M g H, where H = 10 meters. Since kinetic energy is (1/2) m V^2, you can divide out the Mass and say that V^2 increases by gH. g is the acceleration of gravity.

Answer 2

I meant to write (as I did when you asked the question before):
V^2 increases by 2gH.
g is the acceleration of gravity.

Therefore

Vfinal^2 = 30^2 + 2*9.8*10 = 1096 m^2/s^2
Vfinal = 33.1 m/s