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Join Rosie Girl Veronica as she uses a string, a balloon, and a straw to explore propulsion and Newton’s third law of motion – for every action there is an equal and opposite reaction!   

Propulsion is a force that pushes or drives an object forward. Propulsion systems move objects up and forward at the same time. These systems make airplanes fly, and as Veronica shows in the video, rely on the principles of Newton’s third law!

Want to duplicate this experiment at home or in your classroom? Watch the video for an overview, gather the materials listed at the right, and follow the instructions below!

Required Materials

  • 1 balloon
  • 1 straw
  • tape
  • string
  • table

Step-By-Step Instructions

Step 1

Tape a balloon to the bottom of the straw. Make sure you can still blow air into the balloon – don’t tape around it!

Step 2

Tie one end of the string to a table leg or another stationary object.

Step 3

Thread the straw with the balloon attached through the untied end of the string.

Step 4

Tie the other end of the string to the opposite table leg (or other stationary object).

Step 5

Blow air into the balloon.

Step 6

Let go of the balloon and watch what happens! How does propulsion work? How does Newton’s third law of motion come into play?