# physics help me bob!

posted by
**dt**
.

A rock is thrown from the roof of a building with a velocity v0 at an angle α0. The

height of the building is h.

(i)Calculate the horizontal distance traveled by the projectile before it strikes the

ground.

(ii)Show that the speed of the rock just before it strikes the ground is independent

of α0.

(iii)Calculate the value of the launching angle for maximum horizontal distance

when the building height is zero, h = 0.