# A car of 1000 kg with velocity 18 km/hr is stopped by brake of 1000 N. distance covered by it before stopping is

$(a)\;1\;m \quad (b)\;12.5\;m \quad (c)\;162\;m \quad (d)\;144\;m$

$F=ma$
$a=\large\frac{-1000}{1000}$
$\quad=-1 m/s^2$
$v^2=u^2+2as$
$0=u^2+2(-1)s$
$0=\bigg(\large\frac{5}{18}$$\times 18\bigg)^2-2s$
$s=12.5\; m$
Hence b is the correct answer.

answered Jul 15, 2013 by
edited Feb 10, 2014 by meena.p