Jill can use a force of 12N to lift a single box up 5m. How many of these boxes must she lift in a minute to use 60 watts of power?

Answer: 60 of the boxes

Explanation:

Work is said to be done if force is applied to move a body over a distance.

Work done = Force * distance

Workdone by Jill to move a box = 12*5 = 60Joules

Power is the rate of workdone in a specific time. It is measured in Joules/sec

Power = Work done/Time

60=60/time

Time = 60/60

Time=1 second

This means that it took Jill 1second to move a box.

If it takes 1second to move a box using a power of 60watts, this means Jill will move 60boxes in a minute (60seconds) using the same power.