Kids After School Activity: Inertia and Spinning Marbles

By Rachel Miller

Inertia and Spinning Marbles

Inertia is part of Newton’s First Law of Motion.  We see it in action all the time. When you see a rock just sitting outside, the same place every time you walk by it, or when you throw a baseball and it keeps moving through the air even though your hand is no longer pushing it, that is the law of motion in action.  Things that are still will stay still and things that are moving will keep moving – UNLESS, something stops them.

Our kids love exploring principles of science, technology and math, and today we did just that as we created spinning marbles. STEM activities are a way to learn hands-on the emerging concepts from Science, Technology, Engineering and Math fields. We took the principles that we learned at our Sylvan EDGE class and used them to make and observe spinning marbles.

Supplies Needed:

  • A bowl-full of marbles that are all the same size
  • Hot glue gun
  • Flat surface

Inertia and Marbles Glue Gun


Explain to your kids the importance of acting in a safe manner with the glue gun as they can burn themselves with the glue, and then watch them glue the marbles together.  They will want to glue three into a triangle and then add one in the middle of that to make it a pyramid.

Discuss with your kids about how the marble pile is just sitting.  Without any energy or force to move it, those marbles will always just sit right where you put them.  One of the things that is terrific about STEM classes, like the ones being offered at Sylvan Learning as part of their EDGE program, is the emphasis on kids interacting with science and technology principles in a hands on way.  Kids are asked to look at a problem, think critically, and solve it on their own.  We could tell our kids about Newton’s law of motion and what inertia is, but it is so much more meaningful to experience this lesson!

Stand the marbles up on one “edge” or ball and then give it a good spin.  It might take a couple of tries, but what happened?  How long can you get your marbles to spin?  Explain with your kids how gravity will eventually win and the marbles will stop spinning, but inertia keeps the marbles rotating long after you flicked them into action.  What is moving will keep moving until something stops it!

Cluster of Marbles Spinning


Go bigger!  We didn’t stop at a 4 marble pyramid.  You can add another 6 marbles to make an even bigger pyramid of balls.  This one will be harder to get going – but you can do it and it will spin for a long time!  Ask your kids, for things that are bigger, do they take more energy or force to move??

Thanks Sylvan Learning for encouraging my kids critical thinking skills to develop!