If 60 joules of work are done in 3 seconds, what is the power?

If 60 joules of work are done in 3 seconds, what is the power?

• A. 20 W
• B. 180 W
• C. 0.05 W
• D. 60 W

Answer: (A)

Power is the rate at which work is done, measured in watts. It equals work done divided by the time taken. Here, 60 joules of work are done in 3 seconds, so power = 60 J ÷ 3 s = 20 J/s = 20 W. This means energy is transferred at 20 joules per second during the process. If the work were done faster, the power would be higher; if slower, the power would be lower. For reference, 180 W would require delivering 60 J every 1/3 of a second, 0.05 W would spread the 60 J across 1200 seconds, and 60 W would deliver 60 J each second (giving 180 J in 3 seconds, not 60 J).

Power is the rate at which work is done, measured in watts. It equals work done divided by the time taken. Here, 60 joules of work are done in 3 seconds, so power = 60 J ÷ 3 s = 20 J/s = 20 W. This means energy is transferred at 20 joules per second during the process. If the work were done faster, the power would be higher; if slower, the power would be lower. For reference, 180 W would require delivering 60 J every 1/3 of a second, 0.05 W would spread the 60 J across 1200 seconds, and 60 W would deliver 60 J each second (giving 180 J in 3 seconds, not 60 J).