Looking for STEM challenge ideas for kids? How about building some trampolines for marbles! Challenge kids to engineer a marble run that includes a super cool trampoline for the marble to bounce on. Can they bounce a marble off the trampoline and into a container? Then see if they can make the marble bounce off more than one trampoline!
All four of my boys (ages 5-13) loved this project! I could see the wheels turning while they tried to figure everything out! Young kids will love this, but I’d also highly recommend it for middle school (ages 11-13) because kids that age can really make some neat marble runs.
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Here’s what we used to build our marble runs and trampolines:
- PVC pipe – ours is 3/4 inch (inside diameter), although the exact size is not critical.
- Building toys – we used Tinker Toys and wooden blocks
- Small plastic cups and bowls
- Balloons – 12 inch
- Painter’s tape/masking tape
My husband cut the PVC pipe in half lengthwise with a saw and a miter box. It was slow going and it’s not perfect, but the pipes make the perfect marble tracks! We will definitely be using these over and over. Our sections are about 14 inches long.
If you don’t want to do PVC pipe, another great option would be paper towel rolls.
Here’s how to make the trampolines:
First, cut the neck off of a balloon.
Then stretch the balloon over the top of a plastic cup. Ours are from IKEA – they are useful for drinks, but also for so many other things, like scooping water at the water table.
Drop a marble on the balloon, and it bounces!
Then it was time to get to work creating marble runs that included our trampolines! Our first track was simple, and we used cardboard boxes to support the track. We also used masking tape to attach the PVC pipe to the Tinker Toy supports.
In the middle, you can see a PVC pipe connector that we used to join two pipe sections. It’s not a tight fit with the pipes cut in half, but it works!
Then Aidan decided to make the marble run a little bigger and better… With this ramp, the marble hits the trampoline at an angle and flies backward into the plastic container! (The container is under the track.) So cool!
This track started with one trampoline and then a container to catch the marble after it bounced off the trampoline.
But Gresham and Owen expanded it so that the bounced off three different trampolines! The marble never landed on the first one after the ramp, but if they did it just right it would bounce off the next three and into the bowl!
Another day, we tried building a ramp that would allow the marble to bounce off a trampoline and then back onto the ramp again. Aidan made one that worked! He used two pieces of ramp on the bottom section so that the marble would have a better shot at hitting at least one of them.
Physics Concepts to Discuss
This is a great activity for learning about physics concepts! If you hold a marble at the top of the ramp, it has potential energy. This changes to kinetic energy when you let go and the marble rolls down the ramp. The marble gains momentum as it rolls. Momentum = mass times velocity. The marble rolls faster and faster down the ramp because of acceleration due to gravity, so as its velocity increases, its momentum increases as well.
Will the marble bounce higher if it has more momentum when it hits the trampoline? For example, if it rolls down a longer ramp?
Ask kids to observe – how high does the marble bounce if you increase the height of the ramp over the trampoline? Does it bounce higher or the same? (It’s a little hard to tell because it happens to fast, but older kids will enjoy exploring this.)
Have fun exploring!