Overview

The class brainstorms differences in the ways different balloon cars work. Some go straight, some curve, some go faster.  Students complete the redesigns of their wind-ups and balloon cars, and prepare the presentations and explanations of their work.

Materials

• Balloon cars made in previous lessons
• Materials for making balloon cars, for spare parts
• Markers, crayons and craft materials for decorating balloon cars

Procedure

1. Class meeting: Conduct a brief meeting about the differences among the balloon cars students have made. They have probably noticed that some go straight, while others don’t. If students have conducted balloon car races, they may have noticed that some go faster than others. Develop and chart these differences.

2. Redesigning balloon cars: Provide time for students to redesign their balloon cars to make them work the way they want. Some challenges are:

• Make it the locomotive of a train – see how many train cars it can pull
• Make it go faster (for example by adding a second balloon)
• Use two balloons to make it rotate in place
• Make a balloon car that has only three wheels.
• Make a balloon car that has only two wheels.
• Make a balloon sled that has no wheels at all.

3. Science Notebook:

• Explain how you redesigned your balloon car to make it work differently.
• Use diagrams to show what you did.
• How well did your new design work?

4. Outcomes

• Students learn how the design of a balloon car affects its performance.
• Students redesign their vehicles to make them work the way they want.