Newton’s Third Law {and Some Water Fun!}


Science Fun Balloon Boats


Trevor and I worked on this project when I wrote A Project Guide to Forces and Motion for Mitchell Lane Publishers. Since the days are warming up, and you may be ready for some outdoor water play, I thought I’d share it with you. {Though it would make a fun bath toy, too!}

Balloon boats are fun, use up some common recyclables around the house and serve as an excellent example of Newton’s Third Law: For every action there is an equal and opposite reaction.

You blow the balloon up, then release it. Air escapes and pushes back against the balloon. The balloon pushes against the air. The balloon {and attached boat} goes one way and the air goes in the opposite direction.

Simple, right? Ready to try it with your kids?

You’ll need:

  • an empty container {we used a clear plastic produce container}
  • a straw
  • a balloon
  • a rubber band
  • play dough or clay {whatever you have leftover}
  • scissors
  • hole punch
  • an interested scientist


Have your scientist punch a hole in the side of your container about 1/2 inch from the bottom:

Punch a hole for the straw

Hole Punch


Cut the straw in half and put one end in the balloon. Wrap the rubber band tightly around the it to hole the straw and balloon together:

Insert the Straw into the Balloon


Put the straw through the hole in the container with the balloon on the inside and secure it with clay or dough:



Roll some more clay or dough into a ball, and put it in the bottom of the boat to balance it – you might need to put your boat in water to get the balance right:

Rolling clay for balance



Blow the balloon up through the straw, pinch the straw to keep the air in, place the boat in the water and let it go:

Add Fuel to Balloon Boat

Balloon Boat Launch 2


Ask your budding scientist to think about it… What happened? Did your boat go straight? Why? Is there anything that could be done differently to improve your design? This would be a good time to ask them to reflect on the activity in a science notebook if you’re keeping one.

How did this activity demonstrate Newton’s law? What was the action? The reaction?

Sometimes, on a warm day with boats and wading pools, I forgo the science notebook {gasp} and we just play with the science. We can always revisit it later… How are you and your kids playing with science this week?