Today’s lesson was all about viscosity and collecting data on various liquids’ viscosity. Viscosity is fluid friction, which we can describe as the interactions between molecules of a fluid that affect the rate at which that fluid is able to flow.
For our activity, we tested the viscosity of five common fluids that you might find in the kitchen or bathroom cupboard. We made hypotheses about which fluids were more viscous and less viscous based on how they flow. We then set up a test of the viscosity of the different liquids by observing marbles flow through them and measuring the velocity (in seconds) of the marbles. The students tested each liquid three times and recorded how many seconds it took for the marble to flow through each liquid. A data table was used to facilitate the collection of data. Students then calculated the average time (in seconds) for each liquid. Students analyzed their data, identified the relationship between velocity and viscosity in their data, and concluded which liquids were more or less viscous.
The lesson concluded with talking about the importance of reviewing all your data points to ensure that they are consistent and accurate to build confidence in your data.