Mahesh Godavarti

If the car takes 5 s to come to a step, the car slowed down at the rate of 3 m/s2.

The question is asking for "how far", so, we are looking for a linear motion relationship that helps us find the answer to "how far" which would be

\Delta x = v_i \Delta t + \frac{1}{2} a \Delta t^2 .

Let me know how that works out.

Great It works