Answer:
Explanation:
Power is defined as the rate at which the work is done:
[tex]P=\frac{\Delta W}{\Delta t}[/tex]where P = power, ΔW = work done, and Δt = time interval in which this work is done.
Now in our case, when the 60 kg student climbs 1.2 meters, the amount of work he does is
[tex]\Delta W=\text{mgh}=(60\operatorname{kg})(9.8m/s^2)(1.2m)[/tex][tex]=705.6J[/tex]Hence, the student did a work of 705.6 J.
In what time interval did he do this amount of work? We are told that he climbed the stairs in 6 seconds; therefore, Δt = 6 s. Hence,
[tex]P=\frac{\Delta W}{\Delta t}=\frac{705.6J}{6s}[/tex][tex]\Rightarrow\boxed{P=117.6W}[/tex]Hence, the power output of the student is 117.6 watts.
