Activity: Design, Launch, Iterate, Reflect

To complete this challenge, you’ll need some materials, including Popsicle sticks, rubber bands, tape, and 1 plastic spoon. You’ll also need to take notes on your process in a Design Notebook, which can be done either on paper or on a computer.

Now it’s time to apply the Engineering Design Process. As you know the first step is identifying a problem. That can take some time, so here’s a challenge:

Problem:

Create a catapult using only Popsicle sticks, rubber bands, tape, and 1 plastic spoon. It needs to be able to accurately launch a projectile into a container and also be powerful (launch greater than 2 feet).

1. Design Notebook Entry — In your notes (either hand written or on the computer), identify the constraints of the problem, and brainstorm possible designs. At this point, you might want to share and compare your different ideas and select the design solution you think will work the best.
2. Prototype your catapult. Take pictures of your prototype, and use your Design Notebook to document any issues, ideas, or departures you may have made from your initial design.
3. Test your catapult for accuracy. To test accuracy, find a projectile (mini marshmallows work well, as do small change). Launch five of the same projectiles (e.g., marshmallows, pennies, etc.) five times in a row at a container (a small cup or mug works best), and then document how close each projectile landed to the container by taking one picture of all the projectiles where they landed.
4. After testing, look over your prototype. What can and should be modified to increase both accuracy and power? Note your thoughts in your Design Notebook.
5. Now using any other materials you want, iterate your design at least once. That means, build a new prototype (or modify your old one) and conduct the same accuracy test. Take pictures of the new prototype.
6. Record the final results and your thoughts in the Design Notebook.
7. Collect your notes and pictures, and place them all in a single Word document, and upload them below. Note that a picture of a catapult isn’t enough; you need to upload a document that has all of the elements listed above.

Remember, you must be logged in to be able to submit your design document.