If the speed of a truck is reduced to one third of its original value, the minimum distance required to stop will be

$\begin{array}{1 1}(A)\;same\;as\;before \\(B)\;\frac{1}{3} of\; its\;original\;value\\(C)\;\frac{1}{9} of\;its\;original\;value\\(D)\;\frac{2}{3}\;of\;its\;original\;value \end{array}$

$s \alpha u^2$ as $0= u^2 -2as$
$\qquad= > u^2=2as$
Hence C is the correct answer.
edited Aug 13, 2014