The Stopping Distance of a Passenger Car Traveling at 55 m.p.h.

According to the National Safety Council, a lightweight passenger car traveling at 55 m.p.h. can stop in about __________.

Final answer:

A lightweight passenger car traveling at 55 m.p.h can stop in about 140 to 150 feet. This distance is dependent on road conditions, driver reaction time, and vehicle condition. The stopping distance includes the driver's reaction distance and the braking distance.

Explanation:

According to the National Safety Council, a lightweight passenger car traveling at 55 m.p.h. can stop in about 140 to 150 feet under normal driving conditions. Factors that can affect this distance include road conditions (dry or wet pavement), driver reaction time, and the vehicle's condition. The stopping distance consists of both the reaction distance (the distance covered from the time a driver perceives a danger until the braking begins) and the actual braking distance (the distance needed to come to a complete stop after the brakes are applied).

For example, at 55 m.p.h., with an average reaction time of 0.500 seconds, the vehicle travels approximately 40 feet before the driver even begins to apply the brakes. After braking begins, the actual stopping distance can be around 100 to 110 feet on dry pavement. This total stopping distance can significantly increase under wet or slippery road conditions or if the driver's reaction time is slower than average.

If a car is initially traveling at 30.0 m/s (equivalent to 67 m.p.h.), the stopping distances could be longer than for 55 m.p.h., highlighting the importance of allowing more distance for higher speeds and being aware of the road conditions. It is always important to maintain a safe following distance and anticipate potential hazards ahead.