A particle is projected with a speed $u$ at an angle $\theta$ with horizontal from point A. It strikes elastically with a vertical wall at height $h/2$. It rebounds and reaches maximum height $h$ and falls back on the ground at point B as shown in figure. Distances from A to wall and from wall to B are $x_1$ and $x_2,$ respectively, and time to cover $x_1$ and $x_2$ are $t_1$ and $t_2$ respectively. Match the values in column I with the expression in column II.

	Column I		Column II
i	$\sqrt{2}$	p	$\frac{x_2-x_1}{x_2+x_1}or\frac{x_2+x_1}{x_2-x_1}$
ii	$\frac{1}{\sqrt{2}}$	q	$\frac{t_2-t_1}{t_2+t_1}or\frac{t_2+t_1}{t_2-t_1}$
iii	$1$	r	$\frac{u\sin \theta }{g(t_1+t_2)}$
iv	$\frac{1}{2}$	s	$\frac{u\cos \theta (t_1+t_2)}{(x_1+x_2)}$