Work and Power

Multiple Choice

An apple weighing 1N falls through a distance of 1m. How much work is done on the apple by the force of gravity?

• 0 J

• 1 J

• 2 J

• 0.5 J

Multiple Choice

The breaks on a bicycle apply 125N of frictional force to the wheels as the bicycle travels 14.0m. How much work have the brakes down on the bicycle?

• 8.9 J

• 0.1 J

• 139 J

• 1750 J

Multiple Choice

While rowing in a race, John does 3960J of work on the oars in 60.0s. What is his power output in watts?

• 66 W

• 237600 W

• 0.15 W

• 4020 W

Multiple Choice

Using a jack, a mechanic does 5350J of work to lift a car 0.500m in 50.0s. What is the mechanic's power output?

• 9 W

• 10700 W

• 2675 W

• 107 W

Multiple Choice

Anna walks up the stairs on her way to class. She weighs 565N and the stairs go up 3.25m vertically. What is her power output if she climbs the stairs in 12.6s? (FIND WORK FIRST, then power)

• 1836.3 W

• 145.7 W

• 44.8 W

• 3.9 W