Models and Designs. The Drought Stopper Challenge.

The drought stopper system is a black box since we could see what it does, but we couldn't see how it does it.

All Grade 5 students' challenge was to draw a model that explains how you can get 700 mL of water out after putting in only 300 mL. They draw their own model on their science journal. With that drawing of how the model works they made sure to include answers to the following questions in their conversations with other students:

How does your model (or idea) operate?

What observations of the drought stopper support your idea?

As a class we discovered that this drought stopper uses a siphon to produce the interesting behaviour we observed.  A siphon is a hose filled with water, with the outflow end lower than the inflow end.

1.)  The inflow end is on the bottom of the container and the outflow extends below the level of the bottom of the container.

2.)  Pressure makes the water flow out of the  lower end of the hose.  Because water is flowing into the hose from the bottom of the container, water will flow until the container is empty.

To extend what we learned in class students have a double page home/school connection to complete at home.