Question

A vacuum gage connected to a chamber reads 39 kPa at a location where the atmospheric pressure is 92 kPa. Determine the absolute pressure in the chamber?

Answer 1

Answer: 53 kPa

Step-by-step explanation:

Absolute pressure is a pressure value referred to absolute zero or vacuum. This value indicates the total pressure to which a body or system (the chamber in this situation) is subjected, considering the total pressure acting on it.

In this sense, the equation that will be useful in this case is:

`P_(atmospheric)= P_(absolute) + P_(vacuum)` (1)

Where:

`P_(atmospheric)=92 kPa` is the atmospheric pressure

`P_(vacuum)=39 kPa` is the vacuum pressure

`P_(absolute)` is the absolute pressure

Isolating
`P_(absolute)` from (1):

`P_(absolute)=P_(atmospheric) - P_(vacuum)` (2)

`P_(absolute)=92 kPa - 39 kPa` (3)

Finally:

`P_(absolute)=53 kPa=53(10)^(3) Pa` This is the absolute pressure in the chamber