A balloon taped to a straw travels along a taut string when released, demonstrating Newton’s Third Law of Motion: the escaping air (action) pushes the balloon forward (reaction). The setup provides a simple model of rocket propulsion.

1. Cut a length of string (about 3 meters) and thread it through a straw.
2. Secure one end of the string to a wall, desk, or post.
3. Have a partner hold the other end taut and parallel to the ground.
4. Inflate a balloon without tying it, then pinch the neck closed.
5. Tape the balloon to the straw with the open end pointing backwards.
6. Release the balloon and observe how far and fast it travels along the string.

Balloon Rocket Science Experiment for Kids - The Dad Lab:

Balloon Rocket | Rocket Balloons Experiment - One Little Project:

📄 Make a Balloon Rocket - Science Bob: https://sciencebob.com/make-a-balloon-rocket/

• Use different string types (fishing line, yarn, thread) to compare friction effects.
• Add fins or a paper nose cone to stabilize the flight.
• Attach small weights (cargo) to the balloon to see how added mass affects distance.
• Angle the string upward to test how well the balloon rocket can travel against gravity.
• Try balloons of different sizes and shapes to compare propulsion power.

• Use caution when inflating balloons; do not overinflate to avoid bursting.
• Keep balloons away from small children to prevent choking hazards.
• Clear the launch area to avoid tripping hazards with the string.

• What is the force that propels the balloon forward? (The escaping air pushes backward, creating a forward reaction force.)
• How could you make the balloon travel farther? (Use a larger balloon, reduce string friction, or stabilize it with fins.)
• Why does the balloon eventually stop moving? (Air runs out and friction with the string and air resistance slows it down.)
• How is this similar to how rockets work in space? (Both rely on action and reaction forces rather than needing air to push against.)