Question

A cube made of material having a density of `900 kgm^(-3)` floats between water of density `1000 kgm^(-3)` and a liquid of density `700kgm^(-3)`, which is immiscible with water. What part of the cube is inside the water?
A. `1//3`
B. `2//3`
C. `3//4`
D. `3//7`

Answer 1

Correct Answer - B
Let length of each side of cube is `l`
`Mg = B_(1)+B_(2)`

`L_(3) sigmag = (l-x) l_(2)rho_(1)g +l^(2) xx rho_(2)g`
`implies l(900) = (l-x)700+x1000 implies x = 2/3 l`.