Monday, April 29, 2013

Quadratic Catapult!

My students impressed me SO MUCH today!  I am just so excited by the project we're working on and how well they've done so far.

I gave my students a table of available supplies and a budget of $50.  At the end of last week, they previewed this materials list and I showed them a Powerpoint of a variety of photos of catapults constructed from these materials.  I wanted them to do their own research, but barring me checking out mobile labs and supervising web browsing, that wasn't going to happen in school.  Too many of my students don't have internet access at home for me to assign anything for homework that requires the internet.  My pre-selected photos actually worked well because it gave us an opportunity to talk about how certain designs worked. 

Cost for one
Plastic Spoon

Masking Tape
3 feet

Rubber Band

Popsicle Stick

Small Cup

Cardboard (approximately 8”x10”)

Wooden Clothespin

Wooden Pencil

Staple Remover

Paper Clip

Binder Clip



They started off by spending a minimum of 10 minutes planning their design before I let them "purchase" materials.  Construction was full of redesigns, and all but one group worked together well to solve the challenges they faced.  By the end of the hour we spent on the project today, all groups had a working model that they had tested at least a few times.  (Photos to come)

For those of you wondering, the approximate teacher cost for this project (for 50 students in groups of 3 or 4) was about $15, though you likely have most of the materials in your classroom already.  Substitutions are certainly possible.  No groups used a staple remover.  Few chose pencils, paper clips, cups, and clothespins.  I did want to have a large enough variety of materials that students wouldn't recreate the same design in each group.  I also had several students ask to bring in materials but I didn't allow them to do so.  I could have, and it would have increased variety, but I wanted to keep the playing field level for this project. 

One thing to note: I made a model at home just to test out my idea.  It sent the projectile about 5 feet, perfect for a classroom project.  My awesome students, however, have sent their beans flying 40+ feet (from one end of the room to the other).  It was organized chaos in my room today, but all in the name of learning.  So, if you're at all concerned about safety or the discretion that your students would use during this project, it might be good to test outdoors.  Of course, it's pouring rain for three days here, so we're testing inside and making it work.  I actually had the librarian offer her space, too, so I think we're going to try to be really quiet while we test tomorrow!

Tomorrow, the groups will collect accurate data on the distance their bean travels and the time it takes to land.  We'll find an average for each of those data sets and use it to find the equation of the parabola.  I can't wait! 


  1. Awesome! Thanks for sharing with us!

    1. PS! I don't know how I missed you! I am going to add you to my "Blogs I Read" shout outs right now!