Question

A car is moving with speed $2m/s$ crosses a electric post and starts accelerating at a constant rate of $2m/s^2$. How far past the electric post will the car be after $3s$?

• A. $8m$
• B. $9m$
• C. $12m$
• D. $15m$
• E. $18m$

Answer 1

The correct option is D $15m$

Given :

Initial velocity $u=2$ m/s

Acceleration $a=2$ $m/s^2$

Time $t=3$ s

Using second equation of motion:

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

Thus the distance of electric post from the car after $3s$,

$S=2\times 3+\frac{1}{2}\times 2\times 3^2=15m$