The braking distance (in meters) for a car with excellent brakes on a good road with an alert driver can be modeled by the quadratic function $B(s)=.01 s^{2}+.7 s,$ where $s$ is the car's speed in kilometers per hour.
(a) What is the braking distance for a car traveling 30 kilometers per hour? For one traveling 100 kilometers per hour?
(b) If the car takes 60 meters to come to a complete stop, what was its speed?