**Guide :High School **

# A student who weighs 500 newtons climbed the stairs from the first floor to the third floor,15 meters above, in 20 seconds. How much work did she do

A student who weighs 500 newtons climbed the stairs from the first floor to the third floor,15 meters above, in 20 seconds. How much work did she do**Well, the 20 seconds gives us enough information to actually calculate the power she has on her feet :)Well, the work is 500*15=7500J, that is 7.5 kJ or about 18 calories (1 cal is 418J?) The power is that 7.5 kJ divided by 20 seconds: 375W. That's... OK, I suppose...**...