Question

An object floats in a liquid of density 1.2×10kgm with one quater of its volume above the liquid surface. You are required to determine the density of the object

Answer 1

For the equilibrium:

$$mg=\rho_lg(1-0.25)V$$

$$\rho Vg=0.75\rho_lgV$$

$$\rho =0.75\rho_l=0.75(1200)=900\frac{kg}{m^3}$$