A ball is thrown upward from a platform 4.6 m high with a speed of 23 m/s at an angle of 40 o from the horizontal. What is the magnitude of its velocity when it hits the ground?

Answer 1

Regardless of the angle that it is thrown, the kinetic energy at impact will increase by M g H, where H = 4.6 m.

Although you do not know M, it will cancel out when you write

(M/2)Vo^2 + M g H = (M/2)Vinal^2

Vfinal^2 = Vo^2 + 2 g H