Question

A 1-m-tall barrel is closed on top except for a thin pipe extending 4.2 m up from the top. When the barrel is filled with water up to the base of the pipe (1 m deep) the water pressure on the bottom of the barrel is 10 kPa. What is the pressure on the bottom when water is added to fill the pipe to its top?

Answer 1

Answer:

P = 52 kPa

Explanation:

Hidrostatic pressure is defined as the product of the height of liquid (h) by its specific weight (ρ) and by the acceleration of gravity (g).

In the first scenario, the atmospheric pressure is:

$10,000 = \rho g h_{1}\\10,000 = \rho g*1\\\rho g = 10,000$

In the second scenario, h = 4.2 + 1 m. Therefore, the pressure at the bottom of the barrel is:

$P= \rho g h_{2}\\P= 10,000*5.2\\P=52,000\\P=52kPa$

The pressure on the bottom when water is added to fill the pipe to its top is 52 kPa.