Two cyclists who weigh the same and have identical bicycles ride up the same mountain,both starting at the same time.Joe rides straight up the mountain,and Bob rides up the longer road that has a lower grade.Joe gets to the top before Bob.Ignoring friction and wind resistance,which one of the following statements is true?
A)The amount of work done by Joe is equal to the amount of work done by Bob,but the average power exerted by Joe is greater than that of Bob.
B)The amount of work done by Joe is greater than the amount of work done by Bob,and the average power exerted by Joe is greater than that of Bob.
C)Bob and Joe exerted the same amount of work,and the average power of each cyclist was also the same.
D)The average power exerted by Bob and Joe was the same,but Joe exerted more work in getting there.

Question

Quizplus · Accepted Answer

Work is defined as force times distance. Since both cyclists are moving the same vertical distance (height of the mountain) and their weights are the same, the work done against gravity is equal for both. However, Joe, who rides straight up and arrives first, does so in less time, indicating he exerted greater power, as power is work done per unit time.

Two Cyclists Who Weigh the Same and Have Identical Bicycles