Applied Hydraulics #$1\mathrm{.}3\mathrm{.}5$

A $2\mathrm{.}5$ ft diameter cylindrical water tank $($Figure P$1\mathrm{.}3\mathrm{.}5)$ is suspended vertically by its sides. The tank contains water @ $20$ Celsius to a depth $d.$ The force on the bottom of the tank is $920$ pounds. Determine the depth of the water in the tank.