Q6. If a rubber ball falls from a height $h$ and rebounds upto the height of $h / 2$. The percentage loss of total energy of the initial system as well as velocity ball before it strikes the ground, respectively, are :\\
(1) $50 \% , \sqrt { 2 \mathrm { gh } }$\\
(2) $50 \% , \sqrt { \mathrm { gh } }$\\
(3) $40 \% , \sqrt { 2 \mathrm { gh } }$\\
(4) $50 \% , \sqrt { \frac { \mathrm { gh } } { 2 } }$