One way is I have some of the materials that students may need and some others. These are the items that I bring to school:
- bottle caps
- smaller dowel rods (from our shop teacher)
I give them 15 minutes to create a car. I normally have them as a group create the straw and balloon together so they have the same propulsion system. They have 15 minutes to create and test their car before we record them with our iPad. I normally have them record 2-3 times just to make sure, during this time other students are collecting how far the balloon goes and the time.
Our next step is to collect our data.
I ask students to find the speed their car went and ask them to put a graph on Desmos. We then collect our data together as a class and talk about what each line means who's went furthest who had the top speed.