Which requires the most amount of work by the brakes of a car?
A)slowing down from 100 km/h to 70 km/h
B)slowing down from 70 km/h to a stop
C)equal amounts for both

Question

Quizplus · Accepted Answer

The work done by the brakes is proportional to the change in kinetic energy. The change in kinetic energy is greater when slowing down from 100 km/h to 70 km/h compared to slowing down from 70 km/h to a stop, as kinetic energy is proportional to the square of the velocity.

Which Requires the Most Amount of Work by the Brakes