Two identical vessels are connected to each other by a pipe with a tap, the tap is initially closed.

Two identical vessels are connected to each other by a pipe with a tap, the tap is initially closed. One vessel is filled with gas at a pressure of 20 Pa, the other is empty (gas has been evacuated from it). What will be the pressure if you open the valve?

Given:

P1 = 20 Pa – gas pressure in the first vessel;

V is the volume of each vessel.

It is required to find P2 – the pressure in the vessels after they are connected.

According to Boyle-Mariotte’s law:

P1 * V = P2 * 2 * V, hence:

P2 = P1 / 2 = 20/2 = 10 Pa.

Answer: if you open the tap, the pressure will be 10 Pa.