Question

calculate the angle of projection of the projectile if the horizontal range is equal to the maximum hieght attained?

Answer 1

maximum height

H = u²sin²Î¸ / 2g

horizontal range

R = u²sin2θ / g

so, if

H = R ; u²sin²Î¸ / 2g = u²sin2θ / g

or

sin²Î¸ = 2(2sinθcosθ)

or

sinθ / cosθ = 4

or

θ = tan^-1(4) = 75.693^o ~ 76^o