# An electron starting from rest has a velocity that increases linearly with time i.e $v= kt$ where $k=2\;m\;s^{-2}$. The distance covered in the first 3 second is

$\begin{array}{1 1} 9\;m \\ 16\;m \\ 27\;m \\ 36\;m \end{array}$

Answer : 9 m
$dS=kt dt$
$S=\large\frac{1}{2}$$kt^2 \quad= \large\frac{1}{2}$$ \times 2 \times 3 \times 3\;m=9\;m$
$\qquad= 9\;m$
answered Aug 19, 2014 by