How much energy does it take to climb stairs?

[uno]

1. Efficiency is defined as work-out/work-in. Muscles operate with an efficiency of about 20% in converting energy internally into work externally. Accordingly, how much energy will be expended by a 60 kg person in the process of ascending several flights of stairs to a height of 25 m?



2. I was using Wg=mgh



3. I used the formula to get an answer of 14715 J, but I'm not sure where to go from here.

 

[Epsillon]

Eg yes does equal mgh

Now rmbr efficiency is work out (the amount of energy you get) / work in (how much work you actually put in)

Now we know efficiency is 20 percent and what is the work you get out (hint)

 

[uno]

Got it. Thanks.