A 70.0 kg student runs up a stairway to a heigh of 10.0m above the ground in 10.0 s

Question

if the work done in the process is 6860j what is the power generated by the student in kW 

Answer 1

I am surprised the work is given in this problem, because there is sufficient information given to calculate it.  The work done against gravity is

 

work = mgΔh = (70.0 kg)(9.8 m/s²)(10.0 m) = 6860 J, which is the same as the given work.

 

Average power is the work done divided by the time interval over which the work is performed:

 

P = W/t = (6860 J) / (10. 0 s) = 686 J/s = 686 watts = 0.686 kW

 

 

Answer 2

Hi Kamri!

 

Average power is just work done, or energy expended, divided by the time over which it is done or expended.  The base unit is the watt (W), which equals 1 J/s.  To get kW, you have to take number of watts and divide it by 1000.

 

Hope this helps!