A cubical block of wood `10 cm` along each side floats at the interface between an oil and water with its lowest surface `2cm` below the interface. If the height of oil and water columns are `10 cm` each and `rho_("oil")=0.8g/"cc",` find a the mass of the block, b. the liquid pressure at the lower surface of the block.

Explanation

a. For the floating cube.

Weight of the cube`=`Buoyant force
`impliesmg=B_("oil")+B_("water")`
`=8xx10^(2)xxrho_("oil")g+2xx10^(2)rho_(w)xxg`
`impliesm=800xx0.8+200xx1`
`=640+200=840g`
b. The pressure at the lower surface of the cube is
`p_("oil")+P_(w)=10/100xx(1+10^(3))9.8`
`=980N//m^(2)`
`=` (Here we have used `h_("oil")=10 cm` and `h_(2)=2` cm above the lower surface).