Answer:
10 Joules/second
Explanation:
To find the power needed to get up the stairs, we need to divide the amount of work done (30 Joules) by the time it took to do the work (3 seconds):
Power = Work / Time
Power = 30 Joules / 3 seconds
Power = 10 Joules/second
Therefore, it takes 10 Joules/second of power to get up the stairs.