The Challenge

To design and construct a balloon-powered vehicle that will travel along a straight path and the furthest distance.

You Will Need:

  • 1 (750 mL – 1 litre) plastic bottle from pop, water, vinegar, etc.
  • 2 round balloons (circumference when inflated may not exceed 120 cm)
  • 4 35mm film canister lids
  • 6 drinking straws
  • 50 cm of duct tape
  • 2 rubber bands (Format 64, ¼" width x 3½" length)
  • 2 bamboo skewers


Students may use only the materials listed above to construct their vehicles. They have a maximum time limite of one half hour for the construction of their Balloon Buggy. Note: Keep track of the time used by each team to build their buggy. The challenge is to harness the potential energy of a single inflated balloon and design a vehicle powered by this balloon that will roll in a straight path the furthest distance. All materials must be used and contained within or affixed to the buggy (nonfunctional materials must be used as a ballast). The extra balloon may be used if the first balloon breaks or if a team wishes to use a fresh engine for their second attempt. If both balloons break, the vehicle is disqualified.

Regardless of the balloon’s size, its inflated circumference may not exceed 120 cm (a previously measured, cut piece of string can serve as a convenient measuring device). Once a buggy has been launched, it may not be touched until the balloon has deflated, the vehicle has come to a stop, and the distance traveled has been recorded.

Things to Talk About

  • Identify the components of a real car and discuss the purpose of each.
  • Compare and contrast the students’ buggies with "real" cars they are familiar with.
  • Discuss the variables of the design that could be modified to change the distance traveled. Why are these variables important and why would their redesign yield a different result.
  • Discuss how energy is harnessed and used. What sources of energy are used daily to help us accomplish tasks?