A car , starting from rest, accelerates at the rate `f` through a distance `S` then continues at constant speed for time `t` and then decelerates at the rate `(f)/(2)` to come to rest . If the total distance traversed is `15 S` , then
A. `S = (1)/(2)ft^(2)`
B. `S = (1)/(4) ft^(2)`
C. `S = (1)/(72) ft^(2)`
D. `S = (1)/(6)ft^(2)`
