Question

Prove that the maximum horizontal range is four times the maximum height attained by the projectile, when fired at an inclination so as to have maximum horizontal range.

Answer 1

The horizontal range is maximum when the angle of projection is 45°.

So,

Maximum height for angle of projection 45° is,

Therefore, from equation (1) and (2),

 R = 4H

That is, range is 4 times the maximum height attained by a projectile.