A particle of mass $m$ projected with a velocity $u$ making an angle of $30 ^ { \circ }$ with the horizontal. The magnitude of angular momentum of the projectile about the point of projection when the particle is at its maximum height $h$ is :
(1) $\frac { \sqrt { 3 } } { 16 } \frac { m u ^ { 3 } } { g }$
(2) $\frac { \sqrt { 3 } } { 2 } \frac { m u ^ { 2 } } { g }$
(3) $\frac { m u ^ { 3 } } { \sqrt { 2 } g }$
(4) zero

A body of mass $m$ is projected with a speed $u$ making an angle of $45^\circ$ with the ground. The angular momentum of the body about the point of projection, at the highest point is expressed as $\dfrac{\sqrt{Z}\, m u^3}{X g}$. The value of $X$ is $\_\_\_\_$.