The days from July 3 to August 11 are known as the Dog Days of Summer, usually the hottest, muggiest of the year. This is the period when Sirius, the Dog Star, rises at the same time as the Sun. The ancient Romans defined this period and believed the weather was warmer because Sirius was also providing heat for the Earth, hence Dog Days of Summer. So, how can this heat help us with this month’s STEM challenge? Heat rises which is going to be a good fact to know when building your solar updraft tower, which harnesses the Sun’s heat energy to do work. Our version to going to use empty cylinders with a pinwheel attached to the top. The goal is to get the pinwheel to rotate from the heat rising through the solar tower. What materials would be best to use for the tower sections? Do certain items warm up faster or more than others? How can the pinwheel be attached so it can spin freely? How high off the ground should your updraft tower be? Your challenge is to create an updraft tower that uses the Sun’s heat energy to spin the pinwheel the most amount of times. Updraft Tower Example.
Your updraft tower does have some criteria and constraints. Only the materials provided can be used in your design. The tower needs to be at least 1 foot tall. Every group should build and construct the same type of pinwheel for fair testing during the rotations.
*This idea and challenge can be further explored in the Advancing STEM Grade 4 Unit, Full of Potential: The Effects of Energy.
Hints and Tips for Success
By: Clay Nolan, CA BOCES Learning Resources