I tried all the formulas i know but i cannot answer it I really need your help in this question..

Question

A projectile was launched 64° above the horizontal, attaining a height of 10 m. What is the projectile's initial speed?

Answer 1

You can apply conservation of energy to the vertical velocity component, since the horizontal component does not change.

(Vo sin64)^2/2 = g H = 98 m^2/s^2
Vo sin64 = 196
Vo sin64 = 14
Vo = 15.6 m/s

Answer 2

thanks