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 (our lung power), then if mass goes up, then acceleration goes down. If the mass goes down, acceleration goes up.
Then I ask for volunteers and have the biggest, tallest child, the smallest, shortest child, the fastest runner, and the slowest runner come up for a demonstration. The biggest, tallest child might have stronger lung power than the smallest, shortest child. The fastest runner might have stronger lung power than the slowest runner. BUT, that's just a guess. It's not necessarily true. It all depends on how efficient the rocket design is in using the lung power. I try to have the kids think about all these factors before we build the strawckets.
- 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
- Scotch Tape
- Wrap the paper around the straw and tape it down the seam. Make sure it doesn't stick to the straw, and that the straw can slide in and out easily.
- On one end, create a cone, and put a piece of tape around it.
- Now, put the partially built rocket on your straw and blow it. It won't fly very well.
- Now, cut out fins from a piece of an index card and tape it on the rocket. Any place you choose.
- Now, blow it and see how it flies. If it doesn't fly well, take it apart or build another one to make it fly better. Engineering is all about failure and overcoming that failure.
1. Farthest distance
2. 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 just first two challenges.
Here are some pictures from recent classes:
|From a 3rd grade class|
|1st 5th grade class - Distance Rocket Winners|
|1st 5th grade class - Spiral Trick Rocket Winners|
|1st 5th grade class - Boomerang Trick Rocket Winners |
|2nd 5th grade class - Distance Rocket Winners|
|2nd 5th grade class - Trick Rocket Winners|
|Even with the airfoil, I thought this would be too heavy with all the index card paper, but it flew beautifully. Every time. Won the design award.|
|This design had a beautiful, really tight spiral, but after the tape came off, we couldn't duplicate the trick flight. But I did see it, and I couldn't deny her the design award.|
I tell the kids that I want them to push the envelope. Don't play safe. Think outside the box. Failure is good (one of the project's motto is Fail Spectacularly!), and I was extremely happy with this group of kids. I have more classes coming up this week, but I think it'll be hard to beat these designs.
I might update if there's a mind-blowing one.
Enjoy and build with your kids.
NOTE: The project idea came from The Tech Museum's website a few years ago.