Science Smarts: Skateboard rocket science

By Patty Rooks on May 15, 2021.

The month of May has been flying by. Of course, we have the unofficial kickoff to spring coming up next weekend. I know many people will be outside; hopefully enjoying some beautiful weather. Just in case you need something to keep your little scientist busy, here is an activity sure to please. Let’s get started!

Remember to ask an adult before doing this experiment.

Materials

• Skateboard

• 2L diet cola

• Roll of Mentos candy

• Lots of duct tape

• Cardboard

• Scissors

• Science helper

• Safe outdoor location for testing

Procedure

• Find a safe location outside to do your experiment. It is going to get messy!

• Lay the 2L bottle of cola its side on the top of the skateboard. Now you need to assess if it is sitting up high enough. Some skateboards have a bit of a curve on the back of them. If the lid to the bottle of cola is not sitting above this curve, cut some cardboard and shim it up so it is high enough.

• Using the duct tape, securely tape the 2L bottle in place. You do not want it to move or fall off while you are doing your experiment.

• You have to work quickly now with your science helper.

• Tip the skateboard rocket up so you can unscrew the lid to the 2L bottle of diet cola.

• Unscrew the lid, and quickly add the roll of Mentos to the diet cola. As gently as possible, place the skateboard down and let it go. YOU HAVE TO BE QUICK!

• Watch what happens!

What is going on?

If you take a microscope and observed a Mentos candy, you will see that each Mentos candy has thousands of tiny pits all over the surface. These tiny pits are called nucleation sites. All of these little areas on the candies are perfect places for carbon dioxide bubbles in the cola to form and begin to expand. As soon as the Mentos hit the cola, bubbles form all over the surface of the candy and then quickly rise to the surface of the liquid. This pressure needs to escape because there is no more room in that small 2L bottle, so it creates a geyser out the back of the bottle propelling the skateboard forward!

Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community”. Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. Address: #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403.527.5365, email: praxis@praxismh.ca.

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