How to Make an Air-Powered Balloon Car?

This Air Powered Balloon Car teaches kids how to power a craft car with balloon engines. While Playing with this self-made car, your kids can also learn a little bit of knowledge of physic.

Age: 5+         Time: <30min

 Safety 

1. Be careful with the sharp knife.
2. Adult Supervision.

 Materials List 

• Plastic bottle
• Four bottle caps
• Balloon
• Drinking straw
• Wooden stick
• Tape
• Utility knife

 Instruction 

Step 1/7 —Cut four holes on the side of the bottle, which will be used to fix the axles.

Step 2/7 — Use an electric drill to poke a hole in each of four bottle caps. Press each bottle cap onto the ends of the wooden skewers fixed on the bottle through the holes cut before. These four caps are the car wheels and two skewers are the car axles.

Step 3/7 —Place your car on a flat surface and give it a push to test if the car rolls easily.

Step 4/7 —Cut the bottom end of the dropper open. 

Step 5/7 — Cut a small hole in the top of the car and the other one on the tail of the car,  just big enough for the straw to go through. Put your straw through these two holes and fix the straw on the car.

Step 6/7 — Tape the neck of the balloon to the dropper and seal it. Make sure it is completely sealed.

Step 7/7 — Inflate the balloon and release it. The car will run on the ground.

 Scientific Description 

The car moves because of Newton's Third Law of Motion. While the air is escaping from the balloon, it actually gives an opposite force to push the car forward, according to Newton's Third Law of Motion. The principle of the launch of the rocket is Newton's Third Law of Motion too.

 Extensions 

Aside from balloon, can you use other methods to power the car?