Testing Poiseulle's Law: Flow Rate vs Length

[Jodi]

Hi; Could someone please help me with this question: "Suppose you have measured the flow rate for a number of tubes with different lengths but the same radius, how would you graph your data to test Poiseulle's law (Hint: choose the scales of the axes so that the theoretical graph is a straight line)"
Could I do flow rate (change in V)/(change in time) on the y-axis and do length on the x axis? Thanks for your help.

 

[dextercioby]

Flow versus inverse length would give you the linear appearance required of the theoretical graph.

Daniel.

 

[quicknote]

I would suggest graphing your data as a scatter plot with flow rate (change in volume over time) on the y-axis and length on the x-axis. This will allow you to visually see any patterns or trends in your data. Additionally, to test Poiseulle's law, you can plot a theoretical graph on the same plot using the equation Q = (πr^4ΔP)/(8ηL), where Q is the flow rate, r is the radius, ΔP is the pressure difference, η is the viscosity, and L is the length. By adjusting the scales of the axes, you can make the theoretical graph a straight line, which would suggest that your data follows Poiseulle's law. Any deviations or discrepancies from the theoretical line could indicate potential errors or limitations in your measurements. It is also important to include error bars on your data points to show the variability in your measurements. This approach will allow you to effectively test Poiseulle's law and analyze your results.