Answer
If we take the average weight of $m=80kg$, the work required to rotate $2160$ peoples is $W = 337.36kJ$
Work Step by Step
We have the information of the total number of people $n=36\times60=2160$, the wheel's diameter $d=76m$, and the angular speed of the wheel $\omega = 2\pi / 2min = 2\pi / 120 = 0.052 rad/s$.
If we take the average weight of $m=80kg$, the amount of work needed to rotate one person is:
$W_{one}=\frac{1}{2} I\omega^{2}=\frac{1}{2} mr^{2}\omega^{2}$
Substituting the number, we obtain
$W_{one}=156.18J$
For $2160$ people, the amount of work needed is
$W=156.18\times 2160 = 337.36kJ$
