Question

A particle starts moving towards positive $x$-axis with initial velocity $4m/s$. Acceleration of the particle is $2m/s^2$ towards negative $x$-axis. Find the distance (in $m$ ) travelled by the particle in $4s$.

Answer 1

Answer: 8

$s=ut+\frac{1}{2}a{t}^2$
$v=u+at$
$\Rightarrow v=u-2t$
At $t=2s,v=0$
For $t=0$ to $t=2$,
particle moves along $+$ve $x$-direction and
for $t=2$ to $t=4$,
particle moves along $-$ve $x$-direction.

So, total distance travelled
$=\frac{2\times (4{)}^2}{2\times 2}=8m$