The highest barrier that a projectile can clear is 14.5 m, when the projectile is launched at an angle of 31.0 ° above the horizontal. What is the projectile's launch speed?

Answer 1

Only the vertical component of velocity coverts to gravitational potential energy at maximum height H.

(Vo sin31)^2 = 2 g H = 284.2 m^2/s^2
Vo sin31 = 16.86 m/s
Vo = 32.7 m/s