Pressure and Boyle's Law

[franz32]

Hello guys, I got some problems again. Will you be able to help me?

What is the difference between the absolute pressure and gauge presure?

Why is the absolute pressure plotted vs the length of the column of the trapped air instead of the volume of trapped air in the J-Tube?

[Doc Al]

Originally posted by franz32
What is the difference between the absolute pressure and gauge presure?
absolute pressure = gauge pressure + atmospheric pressure

Why is the absolute pressure plotted vs the length of the column of the trapped air instead of the volume of trapped air in the J-Tube?
The length of the column is proportional to its volume.