Build the fastest sail car! A challenge from the Take Off show to try yourself

The Challenge

In the Take-Off Challenge, students build a vehicle that moves exclusively with the help of wind energy. The goal is to construct a sail car that covers a distance of 3 meters as quickly as possible using the wind from a fan.

The challenge combines creative construction with scientific principles such as aerodynamics, wind energy, and friction forces.

What makes it particularly exciting is that there are no building instructions. The students are only given the materials and the task. The teams decide for themselves what the sail car should look like and how it should be built.

Rules

The sail car may only be propelled by the wind from the fan. Pushing is not allowed.
Teams may test and improve their vehicle as often as they like.
The winning team is the one that completes the 3-meter course in the shortest time.

Recommended procedure:

• Form teams of up to 4 people
• 5 minutes planning phase (no building)
• 20–30 minutes building and testing phase
• Then conduct the race with time measurement

Materials

Basic materials per team:

• Cardboard (e.g. a cardboard sheet as the chassis)
• Paper
• Wooden skewers
• Drinking straws
• 1 roll of adhesive tape (e.g. Scotch tape)
• 4 wheels (purchased or homemade)

Additional materials may optionally be added to encourage creativity.

Other materials:

• One or more fans
• Something (e.g. tape) to mark the track
• Optional: measuring tape to measure the course

Let’s go!

Phase 1: Planning time (5 minutes)

Before the actual challenge begins, teams have 5 minutes to plan their design. A planning phase is important so that students do not jump into the challenge without a clear idea. Every team member should be able to contribute their ideas. In research, we would call this step “hypothesis formulation.”

Phase 2: Building and testing phase (20–30 minutes)

After the planning time has ended, teams can start building. The test track should already be defined and marked so that teams can test their vehicle at any time and improve their design accordingly. This is the experimental phase.

Phase 3: The race

Now let the sail cars drive the course one after another and measure the time for each run. The fastest car wins! And anyone who builds a faster car than Joseph can be especially proud 😉
Did your students beat his record of 9 seconds and 50 hundredths? (In Joseph’s defense: the surface was carpet—not the best condition.)

Phase 4: Discussion and conclusion

Which model worked best—and why?
What is most important: the size, the shape, or the position of the sail?
How could teamwork be improved?
Discuss these questions in the final phase.

Even small changes in the design—such as the size, shape, or position of the sail, the aerodynamic efficiency, or wheel friction—can have a major impact on speed.

Tips from our tests

• Wheels are often the hardest part to obtain. Alternatives include homemade wheels made from plastic bottle caps (make a hole in the center with a heated nail) or cut corks.
• For younger students, or to save time, the teacher can help prepare the axles or make them in advance.
• An image of a sailboat can serve as inspiration without giving a specific solution, although it may also limit creative thinking.
• The building time can be adjusted; however, too much time often reduces the challenge’s momentum, while too little time can lead to disappointing results.

Learning objectives

Through the Take-Off Challenge, students learn to:

• understand basic principles of wind power and energy transfer
• explore the effects of aerodynamics and friction in a hands-on way
• plan, communicate, and work efficiently as a team
• learn from tests and mistakes and systematically improve their design

Author: Lucie Zeches (FNR)
Editor: Joseph Rodesch (FNR)