Assuming equal rates of acceleration in both cases,how much longer would it take a car to stop if braking from 56 mi/h than from 28 mi/h?
A)8 times as long
B)4 times as long
C)2 times as long
D)1.4 times as long
E)the same in both cases

Question

Quizplus · Accepted Answer

The stopping distance of a car is directly proportional to the square of its speed. This means that if a car is traveling at twice the speed, it will take four times the distance to stop.

Using this principle, we can find the ratio of stopping distances for a car braking from 56 mi/h and from 28 mi/h.

Stopping distance ratio = (56/28)^2 = 4

This means that it will take four times the distance to stop the car traveling at 56 mi/h as compared to the car traveling at 28 mi/h. Since the rates of deceleration are equal, the time taken to stop the car is directly proportional to the stopping distance.

Therefore, the car braking from 56 mi/h will take 2 times as long to stop as compared to the car braking from 28 mi/h.

Hence, the correct answer is C) 2 times as long.

Assuming Equal Rates of Acceleration in Both Cases,how Much Longer