A car is travelling along a straight road at speed . A hazard suddenly appears in front of the car. In the time interval between the hazard appearing and the brakes on the car coming into operation, the car moves forward a distance of
. With the brakes applied, the front wheels of the car leave skid marks on the road that are
long, as shown in the figure below.
It is estimated that, during the skid, the magnitude of the deceleration of the car is , where
is the acceleration of free fall.
Determine:
The speed of the car before the brakes are applied.
The time interval between the hazard appearing and the brakes being applied.
The legal speed limit on the road is . Use both of your answers in (a) and (b) to comment on the standard of the driving of the car.