Question

A tank 5m high is half filled with water and then is filled to the top with oil of density 0.85 g cm cube. What is the pressure at the bottom of the tank due to these liquid?

Answer 1

A tank 5m high is half filled with water and then is filled to the top with oil of density 0.85 g cm cube. What is the pressure at the bottom of the tank due to these liquid?

**Solution:**

Pressure at the bottom of the tank $(P) =$ pressure by water level $+$ pressure by the oil $= h_{1}d_{1}g + h_{2}d_{2}g.$

Given that

$$h_{1} = h_{2} = 2.5\,m$$ $$d_{1} = 1000\,\frac{kg}{m^{3}}$$ $$d_{2} = 850\,\frac{kg}{m^{3}}$$ $$g = 9.8\,\frac{m}{s^{2}}$$ $$P = 9.8 \times (1000 \times 2.5 + 850 \times 2.5) \Rightarrow P = 45325\,Pa \approx 4.5\,kPa.$$

Answer: $P \approx 4.5\,kPa$.