Intro: Straw Rockets
I usually do 10 projects in a school year (try to do a project a month for most classrooms, and do a few more for my child's classroom), and I try to mix it up so that kids and I don't get bored. BUT this is one project that I go back to every year because kids ABSOLUTELY love this project.
I collect $10/student/year to cover the material expenses, so I'm always searching for inexpensive materials. If you have any ideas, please let me know. Thanks in advance.
Before we start building our strawckets, I explain Newton's Second Law, which says Force = mass x acceleration (I use mass and weight interchangeably in the classrooms).
Over the years, I've learned one thing from the kids of all ages and grades - adults consistently underestimate their ability to create and problem-solve. So, I cover the Newton's Second Law in Kindergarten classes, too, but I use addition instead of multiplication and use visual aids. What I want them to understand is the relationship between the three variables.
If the force is constant, then if mass goes up, then acceleration goes down. If the mass goes down, acceleration goes up.
The idea for the project comes from The Tech Museum in San Jose, but I've developed worksheets and background info that go with the project on my own. I usually take these into the classrooms, but I'll skip them here.
Step 1: Gather Your Supplies
- Boba straws (these are wider straws for pearl drinks served at restaurants, and Asian smoothie shops)
- 8 1/2 in x 2 3/4in strips of paper (fold a copy paper width-wise half, and then half again, giving you four pieces of 8 1/2 in x 2 3/4in strips)
- Index cards or pieces of cardstock paper
- Scotch Tape
Step 2: Fold, Cut, & Tape
- Fold a piece of copy paper width-wise half, and then half again, giving you four pieces of 8 1/2 in x 2 3/4 in strips.
- Cut a piece of 8 1/2 in x 2 3/4 in strip of paper.
- Put a piece of tape on the paper (as see in the photo). This great idea came from a 1st grader two years ago. Before that, I used to tape it while rolled up around the straw.
Step 3: Roll & Tape
- Wrap the paper around the straw and tape down the seam. Make sure it doesn't stick to the straw, and that the straw can slide in and out easily.
Step 4: Making a Nose Cone
- Flatten out one end.
- Fold it in go create a triangular cone.
- After creating the cone, put a piece of tape around it to prevent the air from escaping.
Now, put the partially built rocket on your straw and blow it. It won't fly very well.
Step 5: On to the Fins
- Now, cut out fins from a piece of an index card and tape it on the rocket. Any place you choose.
When I do this project with K to 2nd graders, I usually cut the index cards in half and hand them out. I want to restrict the size of the fins they can create.
Step 6: Done
- Now, blow it and see how it flies.
- If it doesn't fly well, tweak it. Take it apart or build another one to make it fly better.
Engineering is all about failure and overcoming that failure.
Step 7: Additional Comments:
When I do this project, I give the students two challenges:
- Farthest distance
- Trickiest rocket - boomerang and tight spiral (what I'm looking for is an indication that there was some thought behind the design)
Sometimes I change things around by asking the kids for accuracy, but they kids are pretty challenged year after year by these two challenges.
Step 8: Some Awesome Designs From Elementary School Kids:
Curiosity. Imagination. Perseverance. And FAIL SPECTACULARLY!
These are the things we talk about during our science project time. Failure is OK, as long as you learn from it and keep going. And if you're going to fail, push the envelope and fail spectacularly!
Students often come up to me and ask what the right answer is or how to do it right. And I tell them that there is no one right answer. There are many possible right answers, and they should try to find as many as they could. In a given class period, some highly self-motivated students design, test, and make more than five strawkets.
I hope you have a lot of fun with this project.