A totally reflecting disk has radius $8\mathrm{.}00$ mm$,$ thickness $4\mathrm{.}00$ mm$,$ and average density $7\mathrm{.}00102$ kg$/$m$3$kg$/$m$3.$ A laser has an average power output PavPav spread uniformly over a cylindrical beam of radius $2\mathrm{.}00$ mmmm$.$ When the laser beam shines upward on the disk in a direction perpendicular to its flat surface, the radiation pressure produces a force equal to the weight of the disk.