Roller Coaster STEM Project


“Mrs.” Science Demo Guy here 🙂

With 2 boys home sick from school (sick enough for the school to make them stay home, not sick enough to have a boring day) I decided that the TV and iPad were NOT going to be the plan for the entire day. Inspired by Frugal Fun for Boys and Girls “Straw Roller Coaster” STEM project, ( ) I set up an open-ended STEM activity for my “sick” boys to have fun with. I gave them a number of different materials to use (mostly purchased at Dollar Tree, one of the BEST stores in the universe) and told them to build a roller coaster for a ping pong ball…showing them the example from Frugal Fun.

stem materials

I gave them duct tape to use….if we did this again I’d provide masking tape instead. My fingers are a bit raw from tearing off an infinite number of small pieces of duct tape.

Calvin (5 yrs) was VERY apprehensive about the task of building a rollercoaster from scratch and almost completely refused to do the activity. I talked him into it and he was so proud of his outcome, “Doesn’t it look like a 6 year old built this!?” Zach (7) was pretty uncertain as well—he didn’t think his coaster would be successful but was ready to give it a whirl.

Plan / Design:
They started out by drawing pictures of what they want their coasters to look like.

STEM roller coaster

Then construction began. The longer they spent building, the more and more excited they became about their creations!! Hudson (2 yrs) was “helping”…the older two didn’t appreciate his help 😉

building the structure

building 2

Zach was excited with his outcome, “isn’t it amazing that it actually works?!” I especially like the ring of fire at the end of his coaster.


Calvin was really proud of his creation as well!

calvin's stem rollercoaster

I asked Zach what he thought would make his coaster better. At first he proudly said “nothing!”…but after thinking it through, he wanted to add a jump at the end.

roller coaster kids science project

Calvin decided to build another ramp AND a ball holder at the top of the big ramp.


Science behind the activity
At the end we talked about inertia and how gravity is the force that makes the ball move.

Inertia is the resistance of any physical object to any change in its state of motion; this includes changes to its speed, direction, or state of rest. It is the tendency of objects to keep moving in a straight line at constant velocity.

Errrrr….boys, that means…your ping pong ball isn’t going to move unless a force makes it move —which was what? Zach, “gravity”…yes, yes you are right buddy. Good job. It’s also not going to change direction unless it’s guided by the edges of the coaster.

As for how REAL roller coasters work, well, I’ll leave it to the guys in this video to explain 🙂

We ended up watching a number of other cool roller coaster videos. The video I linked to is totally safe but some of the others have a few PG words.

This whole project consumed over an hour of our time AWAY from the iPad and TV…minus the time spent watching roller coaster videos on my computer. Now for lunch, “quiet book” time (more like, come out of your room and interrupt mom time)…and then back to the mindless entertainment provided by Netflix…