Question

A car accelerates uniformly on a straight road from rest to a speed of $180km{h}^{-1}$ in $25s$ . Find the distance covered by the car in this time-interval

Answer 1

Since the car accelerates from rest so the initial velocity is zero

By using the law of motion and substituting the values given we get

$v=u+at$

$180\times \frac{5}{18}\frac{m}{\sec }=0+a\times 25\sec$

On solving we get the acceleration as

$a=2\frac{m}{{\sec }^2}$

The distance covered by the car in this time interval is given as

$S=ut+\frac{1}{2}a{t}^2$

$S=\frac{1}{2}\left(2\right)\times {\left(25\right)}^2=625m$

Hence the distance travelled is $0.625km$