A car moving at 30m s−1 along a straight level road is brought to a speed of 15m s−1 while covering 90m under uniform retardation.
a. (i) Calculate the magnitude of the retardation.
b. (ii) Find the time taken for this change in speed.
c. (iii) If the same retardation continues, determine the additional distance the car will travel before coming to rest completely.