Two stones are projected from the top of a cliff $h$ metres high, with the same speed $u$, so as to hit the ground at the same spot. If one of the stones is projected at an angle $\theta$ to the horizontal then the $\theta$ equals\\
(1) $u\sqrt{\frac{2}{gh}}$\\
(2) $\sqrt{\frac{2u}{gh}}$\\
(3) $2g\sqrt{\frac{u}{h}}$\\
(4) $2h\sqrt{\frac{u}{g}}$