Question

A tank $5m$ high is half filled with water and then is filled to the top with oil of density $0.85gc{m}^{-3}$. The pressure at the bottom of the tank, due to these liquids, is

• A. $1.85g$
• B. $89.25gdynec{m}^{-3}$
• C. $462.5gdynec{m}^{-2}$
• D. $500gdynec{m}^{-2}$

Answer 1

Answer: (C)

$462.5gdynec{m}^{-2}$

We know that the pressure increases as we go deep into a liquid. The relation is given by $\Delta P=\rho g\Delta h$

Given that the tank is half filled with water and half with oil.

Thus, $h_{\text{oil}}=2.5\text{m}$ and $h_{\text{water}}=2.5\text{m}$

Thus, pressure at the bottom of the tank is $\Delta P=\Delta P_{\text{oil}}+\Delta P_{\text{water}}=0.85\times 250g+1\times 250g=462.5g{\text{dyne cm}}^{-2}$