A student has been asked the following question:Calculate the work done when an elevator with a power rating of 3 kW ascends for 25 seconds.They carried out their calculation using the following steps:P = 3 kW = 3000 Wt = 25 secondsP = W / t3000 = W / 25W = 3000 x 25W = 75 000 J = 75 kJHas this been answered correctly?They did not convert kilowatts into watts.There was an error in the calculation on one of the lines of working.This has been calculated correctly, but they have used incorrect units in the final answer.This has been calculated incorrectly due to misreading the numbers in the question.This has been calculated and answered correctly.

A student has been asked the following question:Calculate the energy transferred when an elevator with a power rating of 4 kW ascends for 2 minutes.They carried out their calculation using the following steps:P = 4 kW = 4000 Wt = 2 minutesP = E / t4000 = E / 2E = 4000 x 2E = 8000 JHas this been answered correctly?No, they did not rearrange the equation correctly.Yes, they have calculated this correctly.No, they forgot to convert the kilowatts into watts to use in the calculation.No, they did not convert time into seconds.No, they have given their answer in joules when it should be in kilojoules

A student has been asked the following question:A 2.5 kW cement mixer provides 50 kJ of work mixing the raw materials.Calculate the time the cement mixer was on for.They carried out their calculation using the following steps:P = 2.5 kW = 2500 WW = 50 kJ = 50 000 JP = W / t2500 = 50 000 / t2500 x t = 50 000t = 50 000 / 2500t = 20 minutesHas this been answered correctly?They made an error when rearranging the equation.This has been calculated correctly, but they used incorrect units.This has been calculated and answered correctly.This has been calculated incorrectly due to misreading the numbers in the question.They did not convert kilowatts into watts.

Power = 3 kWWork done = 825 kJCalculate the time.Time = _____ s

Three units are given in the statements as follows:I.   Newton × metreII.  JouleIII. Kilogram × (metre)–2 × (second)2Which of the statements given above are the units for work done?

Power = 400 WTime = 2.5 minutesCalculate the work done.Work done = _____ kJ