The density of the plastic block of cork is 600 kg/m³.
The density of the oil is 800 kg/m³.
The specific gravity of the cork in water is the fraction of the cork submerged in the water.
S.G = 1 - ²/₅
S.G = ³/₅ = 0.6
The density of the cork is calculated as follows;
[tex]S.G = \frac{\rho_c}{\rho _w} \\\\\rho_c = S.G \times \rho_w \\\\\rho_c = 0.6 \times 1000\ kg/m^3\\\\\rho_c = 600 \ kg/m^3[/tex]
The density of the oil is calculated as follows;
S.G = ⁶/₈ = 0.75
[tex]S.G = \frac{\rho_c }{\rho_o} \\\\\rho_o = \frac{\rho_c }{S.G} \\\\\rho_o =\frac{600 \ kg/m^3}{0.75} \\\\\rho_o = 800 \ kg/m^3[/tex]
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