Physics Concept Help, Velocity/acceleration?

A car starts from rest and accelerates at a constant rate in a straight line. In the first second the car moves a distance of 4.0 meters. How much additional distance will the car move during the second second of is motion.

I'm not sure I understand the concept behind the problem, can someone explain the concept to me?

ANS: The additional distance is 12.0 meters

The speed is increasing at a constant (linear) rate, so the distance moved per second is increasing at a quadratic (squared) rate.

Calculate the acceleration rate for t=1 second, starting from rest:
distance s = 0.5a*t^2 = 4 m
so a = 8 m/s^2

So the total distance after t=2 seconds will be:
s = 0.5a*t^2 = 0.5 * 8 * 2^2 = 16 m

So the additional distance from t=1 to t=2 is 16 – 4m = 12m

Note:
Could also calculate the additional distance by using
s = u*t + 0.5a*t^2
where u = speed after 1 sec, and t=1 second (from 1 to 2 sec):
u = at = 8*1 = 8m/s
s = 8*1 + 0.5*8*1 m = 8 + 4m = 12m