Determine the pressure drop in cm of HO at the onset of fluidization when catalyst particle having a density of $1\mathrm{.}8$ g$/$cc are fluidized with liquid petroleum fraction having a density of $0\mathrm{.}8$ g$/$cc$.$ The static bed height is $200$ cm and the bulk density of the bed is $0\mathrm{.}96$ g$/$cc