Science Smarts: The magic straw trick

By Patty Rooks on April 9, 2021.

I am often told that science is boring or not fun at all. To be honest, I can agree, BUT only sometimes.

Yes, it can be onerous memorizing and learning the fine details about a scientific concept. That is why as educators, we need to supplement the “boring” work with some exciting hands-on activities.

I am a big supporter of learning by doing. Not everyone can memorize or learn by reading and getting in there and yes, getting dirty is the way some of us learn. I encourage all of you out there to try something new, easy and do not be afraid to make a mess (it can be fun!).

Here is a simple activity to get you started!

Remember to ask an adult before doing this experiment.

Materials

• Quite a few plastic disposable drinking straws

• A couple of potatoes

Procedure

• Your challenge here is to push the straw through the potato without breaking or even bending the straw. It has to go all the way through to the other side. Remember when you are doing this to carefully hold the potato in one hand and make sure your fingers and hand are out of the way as you try to force the straw into the potato.

• How did you do? The best part of any experiment is trying to figure it out. This one is a bit tricky, so I really need you to persevere!

• OK, I will help. If you need to get a new straw and potato.

• Hold the straw firmly in your hand, grasping your fingers around it. Place your thumb on top of the straw.

• Hold your potato firmly in the other hand – remember to keep your fingers and hand out of the way.

• In one quick sharp motion stick the straw into the potato.

• What happens?

What is going on?

After I provided you with some instructions, you should have easily been able to push the straw into the potato and out the other side. The secret here is inside the straw. Hmmm…you might say that there is nothing inside the straw. You are incorrect. There is air inside of the straw.

By placing your thumb over one end of the straw, you are trapping all of those invisible air molecules inside the straw. This air then provides strength to an otherwise flimsy straw. This trapped and compressed air makes the straw strong enough to go through that very tough potato flesh and out the other side.

If you want to keep exploring why not try other fruits and vegetable?

Do not forget the deadline for the Kiwanis Regional Science Fair (virtual) is fast approaching. Junior and senior high students need to have everything complete and uploaded by April 16 and the elementary students by April 23. Visit the Praxis website for more information and the links to register.

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.

23
-22