5、Braking and Stopping

   Two important factors that influence the distance you take to stop a car are how quickly you react to danger and the speed at which you are traveling.

   The average reaction time (from the time driver sees danger to when he/she applies the brakes) is two seconds. Reaction time is affected by the driver’s levels of tiredness, alcohol and concentration（集中注意力）.

   Braking distance ( the distance travelled after the driver has applied the brakes) depends on factors such as your speed, type of brakes, type pressure and tread(车胎花纹), vehicle weight, wind speed, slope(坡度) of the road, surface smoothness and the driver’s braking technique.

Remember: As your speed doubles, your total stopping distance more than doubles.

   At 60km/hr a vehicle will travel 34 meters while the driver is reacting to the danger, and another 21 meters before the car comes to a stop. Total stopping distance is 55 meters.

   Total stopping distances shown in the graph are for vehicles with good brakes, on a dry smooth level road surface, and fitted with good tyres with the correct depth of tread.

 

53． If I am driving at 100 km/hr, my total stopping distance is about _____.

   A. 58m          B. 100m      C. 56m      D. 113m

54． If I am driving at 70 km/hr, the distance I travel after I apply the brakes is about ______.

   A. 39m          B. 28m         C.70m      D. 67m

55． If I am alert (警觉) and my car is in good condition, my total stopping distance will be ______ if I am tired and my car is in bad condition.

  A. more than                   B. less than     

  C. the same as                  D. greater than