A body is projected horizontally from the top of a tower of height h = 20 m with a speed u = 20 m/s  . Then the angle, measured with horizontal, at which the body will strike the ground is

Just before striking the ground ' horizontal component of the velocity of the body vh = 20 m/s Similarly vertical component of the velocity of the body vv = 2gh = 2×10×20 m/s =20 m/s .Therfore angle between velocity vector and horizontal = tan-1vvvh = tan-12020 = 450