Question

A car travels at 64 mi/h when the brakes are suddenly applied. Consider how the tires of a moving car come in contact with the road. When the car goes into a skid (with wheels locked up), the rubber of the tire is moving with respect to the road; otherwise, when the tires roll, normally the point where the tire contacts the road is stationary. Assume the coefficients of friction between the tires and the road are ìK = 0.80 and ìS = 0.90.

(a) Calculate the distance required to bring the car to a full stop when the car is skidding.
(b) Calculate the distance required to bring the car to a full stop when the wheels are not locked up.
c) How much farther does the car go if the wheels lock into a skidding stop? Give your answer as a distance in meters and as a percent of the nonskid stopping distance
(d) Can antilock brakes make a big difference in emergency stops? Explain.