Balloon Rocket

Instructions

  • Attach one end of the string or fishing line between two fixed points, creating a "track."

  • Thread the drinking straw onto the string so that it can move freely along the track.

  • Inflate the balloon and pinch the end to prevent air from escaping.

  • Tape the balloon to the straw, ensuring it points in the direction of the track.

  • Release the balloon, and time how long it takes for the rocket to travel from one end of the track to the other.

Materials

  • Drinking straw

  • Balloon

  • Tape

  • String or fishing line

  • Stopwatch or timer

Questions:

  • How did the size of the balloon affect the rocket's speed and distance?

  • What happens to the rocket as the air escapes from the balloon?

  • How could you change the design to make the rocket go faster or farther?

  • Can you calculate the average speed of the rocket based on the recorded times?

What is happening?

Newton's Third Law (for every action there is a reaction) provides a basic explanation for how a rocket engine works. The air trapped inside the balloon pushes out the open end, providing an “action”. The balloon's resulting motion is the “reaction”.