Given data:
Weight of the student;
[tex]\begin{gathered} F=mg \\ =556\text{ N} \end{gathered}[/tex]Height;
[tex]h=4.0\text{ m}[/tex]Time;
[tex]t=25\text{ s}[/tex]Part (a)
The work done by the student is given as;
[tex]W=Fh[/tex]Substituting all known values,
[tex]\begin{gathered} W=(556\text{ N})\times(4.0\text{ m}) \\ =2224\text{ J} \end{gathered}[/tex]Therefore, the work done by the student is 2224 J.
Part (b)
The power is defined as the rate of doing work. Mathematically,
[tex]P=\frac{W}{t}[/tex]Substituting alll known values,
[tex]\begin{gathered} P=\frac{2224\text{ J}}{25\text{ s}} \\ =88.96\text{ W} \end{gathered}[/tex]Therefore, the power output of the student is 88.96 W.