A vessel contains oil (density `= 0.8 g//cm^(3)`) over mercury (density `= 13.6 g//cm^(3)`). A uniform sphere floats with half its volume immersed in mercury and the other half in oil. The density of the material of sphere in `g//cm^(3)` is

Options

A. `3.3`
B. `6.4`
C. `7.2`
D. `12.8`

Answer

C

Explanation

A vessel ………….
Weight = Buoyant force

`V_(rho_(m)g)=(V)/(2)rho_(Hg)g+(V)/(2)rho` oil
`r_(m) = (rho_(Hg)+rho_(oil))/(2) = (13.6+0.8)/(2) = (14.4)/(2) = 7.2`