
I have always wanted to incorporate catapults into the quadratic unit, but frankly, the catapult designs I’ve always come across seemed complicated and daunting. So I was very excited to come across this design made out of craft sticks and rubber bands.
Here’s the link for video instructions:
Craft Stick Catapults
I don’t plan on buying the kits, as craft sticks and rubber bands are easy enough to get a hold of. As for the basket, I’m sure that could be made either with masking tape, or by simply gluing down a washer or a nut. As far as a good projectile, I’m thinking Skittles.
After building the catapults, students would then have to measure how far down they pull their basket (the height of the basket from the ground), the distance and time in the air of their projectile, and then model the quadratic equation.
The other thing that I really like about this design is that it makes it easy to adjust the settings. For example, since the catapults in the video are 9 craft sticks thick, students could easily change it to 8 or 10 craft sticks thick, and model those equations too. And then maybe come to some conclusion as to how many craft sticks they would need to have the projectile go x distance.
**11/10 update: Actually, I don’t think there would be a significant difference between 8, 9 or 10 craft sticks. Maybe just compare between 3 and 9 or something like that.**
Just mulling over ideas…
**11/18 update: I think this would have to be done outside to keep the skittles from bouncing around so much. Also, instead of changing the number of craft sticks, students could change the initial height of the catapult by first placing it on the ground, and then placing it on something higher, like a picnic table (there happens to be some picnic tables in the courtyard of our school).