Question

A car moving with an initial velocity of $60\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s$}\right.$ is brought to rest in $30seconds$. Calculate the acceleration?

Answer 1

Step 1: Given data

Initial velocity, $u=60\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s$}\right.$

Final velocity, $v=0\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s$}\right.$

Time, $t=30s$

Step 2: Formula used

I^st equation of motion

$v=u+at$

Step 3: Calculation for acceleration

$0=60+a\times 30$

$$\begin{gathered} a=\frac{60}{30} \\ a=2\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s^2$}\right. \end{gathered}$$

Hence, the acceleration of the car is $2m/s^2.$