$\frac{ h }{2}=\frac{1}{2} gt _{1}^{2}$
For total height $h$
$h =\frac{1}{2} g \left( t _{1}+ t _{2}\right)^{2}$
$\frac{1}{\sqrt{2}}=\frac{ t _{1}}{ t _{1}+ t _{2}}$
$1+\frac{ t _{2}}{ t _{1}}=\sqrt{2}$
$\frac{ t _{1}}{ t _{2}}=\frac{1}{\sqrt{2}-1}$
$t _{2}=(\sqrt{2}-1) t _{1}$
(બંને ટ્રેક વચ્ચેનું અંતર નહિવત લો)