Marshmallow Catapults!

Ever imagine yourself back in the middle ages fending off dragons while hurtling giant marshmallows with powerful catapults at the walls of an evil castle in order to rescue your fellow villagers? What was that? Hurtling marshmallows?? Well, we don’t want to hurt anyone, so marshmallows it is!

Actually, marshmallows and catapults can be useful tools for teaching basic principles in math and science including… Graphing Interpolation Extrapolation Dependent & Independent variables Controlling variables Collecting & presenting data

Let’s look at the setup… Catapult Launch lever Artillery Marking powder

Research questions: What is the relationship between tension applied to the rubberbands (# of turns) and projectile distance? What are the differences between projectile distances of the small and large marshmallows?

Variables What is the independent variable? What is the dependent variable? What variables need to be controlled?

Issues to consider… How many turns will you test? (Try at least 5 different settings) How many trials should you run for each setting? Will you “throw out” any data?

Tasks… Perform your catapult investigations. Create data tables to record your data. Create appropriate graphs.

How could we use this experience to introduce interpolation and extrapolation? What are some possible follow-up questions to engage your students’ critical thinking? What would happen to projectile distances if the marshmallows were wet? At what point does increasing tension actually reduce projectile distances? Why does this occur? What are the advantages and disadvantages of pooling all of the class data? How could the catapults be modified to make them more effective?