# Visualizing Boyle's Law (PV = constant)

Mechanical EngineeringUploaded 23 March 2015

A piston was used to compress a cylindrical air volume to half of its initial volume. It can be visualized that the pressure of air rising to a value which is twice the initial value as the volume of air is compressed to half of its initial volume.

## CommentsAdd Comment

The best way to determine a relationship is to plot a graph that gives a straight line.

At this point we (theoretically) don’t know the relationship, so we plot V vs. P to see what the plot looks like.

We plot pressure as the independent variable (along the horizontal or x axis) and volume as the dependent variable (along the vertical or y axis).

You could do this by hand, but it is more convenient to use a computer to do the job for you.

Your graph, as in the figure, looks like a hyperbola.

The equation for a hyperbola is y=kx. It looks as if we should try a plot of V vs. 1P. Thanks lissacoffey http://qwikfix.co.uk/sky-customer-services/