Balloon Powered Car
Learn how air pressure powers a homemade racer across the floor. We’ll give you step-by-step instructions on how you can build your own race car and then use air pressure to race it across a surface.
- Cut one of the straws in half.
- Tape both pieces of the straw
to one side of the water bottle.
- Cut the wooden skewer in half and push each piece through one of the straws (axles).
- Have an adult help to make a hole directly in the center of each plastic bottle cap.
- Press each bottle cap onto the ends of the wooden skewers.
- Put your car down on a flat surface.
Test if the car rolls easily and coasts for a bit before stopping.
- Tape the neck of the balloon around one end of the other straw.
- Cut a small hole in the top of the water bottle, just big enough to push the straw through.
- Push the free end of the straw through the hole and out the mouth of the bottle.
- Use tape to secure the straw to the bottle.
- Blow through the straw to inflate the balloon, then put your finger over the tip of the straw to trap the air.
- Put the car down on a flat surface and release your finger.
- What happens when you release your finger?
- What adjustments you can do to make the car go farther.
- What happens if you inflate the balloon more?
- What happens if you adjust the direction the straw is aimed?
- Does it work best if the straw is aimed straight back?