Answer:
496.57492 kg/m³
Explanation:
[tex]P_a[/tex] = Atmospheric pressure = 101300 Pa
[tex]\rho_w[/tex] = Density of water = 1000 kg/m^3
[tex]h_w[/tex] = Height of water = 21.8 cm
[tex]h_f[/tex] = Height of fluid = 30 cm
g = Acceleration due to gravity = 9.81 m/s²
[tex]\rho_f[/tex] = Density of the unknown fluid
Absolute pressure at the bottom
[tex]P_{abs}=P_a+\rho_wgh_w+\rho_fgh_f\\\Rightarrow \rho_f=\frac{P_{abs}-P_a-\rho_wgh_w}{gh_f}\\\Rightarrow \rho_f=\frac{104900-101300-1000\times 9.81\times 0.218}{9.81\times 0.3}\\\Rightarrow \rho_f=496.57492\ kg/m^3[/tex]
The density of the unknown fluid is 496.57492 kg/m³