This lab is super inexpensive and so much fun! Students construct a “car” that runs on the power of a single balloon expelling air. Most of the materials are scavenged – water bottles, bottle caps, straws, etc. The activity takes 120 minutes including testing, data collection, and completing the lab questions for the easier version ad 150 minutes for the advanced version. This is real science with real calculations.
My files include a simple version for lower grades (calculating average vel