Design and build two catapults. Each catapult will undergo three different tests to determine accuracy and power.
I have tried several versions of this challenge with my middle school students, and I believe the most successful activity is to have students build two catapults. Working in teams, students brainstorm ideas, select the top two designs, and complete three tests to determine the winning design. Ensure students have a key design difference between the two such as a different base, launcher, or axle.
The best way to set-up the activity is to show pictures and videos of various catapult designs. Discuss what are the basic features of a catapult. Great resources include: TeachEngineering, Science Behind Catapults, and Pumpkin Chunkin Video. I also encourage reviewing the engineering design process and stressing the importance of testing. I really like this PBS resource on using the engineering design process for STEM challenges.
To determine a materials list, I researched several ways to build a catapult as well as experimented at home. I decided to have the following available during the project:
- Popsicle sticks (thick and thin)
- Masking tape
- Plastic cups
- Coke cans
- Rubber bands (various sizes)
- Soup cans
- Plastic spoons
- Bottle caps
You can make all materials available to students or incorporate budgeting by adding a price tag to each supply. I kept it simple by making all supplies available, and I did not have any issues. Once you introduce the various supplies, I found it important to give a couple of examples. I demonstrated how to make a simple coke and rubber band catapult and pointed out the main features. Encourage students to think outside the box with the supplies provided!
Once students have built their catapults, it is time to launch! These three stations can be adapted to your space, but make sure students record results as they go.
Station 1 - Accuracy Cotton balls and a bowl make-up this station. The bowl will be in a set location (works well on the floor). Teams will have 2 test runs to determine launching distance. Then, from a set distance, students will launch their cotton balls. Record how many make it into the bowl out of 5 attempts.
Station 2 - Power Mini marshmallows work great for this one. Set-up a launch line using masking tape. Students launch 3 times per catapult and record each distance using a measuring tape. If it is too much hassle to record the distance, have students launch both catapults and mark which one went farthest for each trial.
Station 3 - Tower Build a tower out of small plastic cups. Mark a set distance of about 3 feet that students must launch behind (they can go farther back). Use beans or a heavier item to knock over the tower.
Students will have a blast with this challenge! I love seeing all the creative designs, and you can see a sample in the picture below. You can also get more catapult ideas at these great websites:
A great part of the catapult challenge is the ease of adding math to the activity. You can download our product for handouts that include math problems or some ideas to add your own:
Original article and pictures take http://www.vivifystem.com/blog/2014/12/23/catapult-challenge site