A particle of mass $m$ is dropped from a height $h$ above the ground. At the same time another particle of the same mass is thrown vertically upwards from the ground with a speed of $\sqrt{2gh}$. If they collide head-on completely inelastically, the time taken for the combined mass to reach the ground, in units of $\sqrt{\frac{h}{g}}$ is:\\
(1) $\sqrt{\frac{1}{2}}$\\
(2) $\sqrt{\frac{3}{4}}$\\
(3) $\frac{1}{2}$\\
(4) $\sqrt{\frac{3}{2}}$