In the first experiment, the spout on the lower tank remains closed; in the second, the solution flows from both tanks at the same flow rate.
Prior to experimentation, students are asked to predict the outcomes and sketch results.
Following experimentation, students develop mathematical models and use them to determine the amount of drink powder in the lower tank at the end of each experiment.
Specifically, first-order separable and linear differential equations are employed.
Additional components of the lab invite students to consider a situation in which tank outflow rates differ (i.e. changing tank volume over time) and, further, a scenario in which pollution is entering and leaving a lake via streams.