March 11, 2023
It’s Not What You Think
The latest Praxis ‘Science Smarts’ column in the Medicine Hat News. The article may also be found in the Medicine Hat News (paper) or digital copy at https://medicinehatnews.com/life/local-life/2023/03/11/science-smarts-its-not-what-you-think/ or via PressReader at https://www.pressreader.com/article/281732683708416.
I am always looking for fun and quick activities to do when I am able to visit all the young scientists in the classroom. They help me show the Scientific Method and how this is applied to the experiments that we are doing.
This activity is particularly interesting as it does not do what many of them hypothesize.
Let’s get started!
*Remember to ask an adult before doing this experiment.
Materials:
- 2 empty pop cans
- 24 drinking straws
- Ruler
- Table to work at
Procedure:
- Using a ruler, lay out all but one of the straws one centimetre apart and parallel to one another.
- Place the two empty cans in the middle of the straws (standing up). Move them about five centimetres apart from one another trying to keep them as close to the middle of all the straws as you can.
- Make a hypothesis — what do you think will happen and why?
- Using the remaining straw, blow a steady stream of air BETWEEN the two empty cans.
- Observe.
- Was your hypothesis proven or disproven?
What is going on?
Most people will expect the cans to roll apart from each other. You would have observed that the cans actually roll towards each other. Hmmm… this is due to a special scientific principal know as Bernoulli’s Principle.
The Bernoulli Principle states that the pressure of a liquid decreases as its velocity increases. With our experiment here that means that as you blow a steady stream of air between the two empty cans, the velocity of the air between the two cans increases, and the pressure that the air is applying to the inner sides of the cans decreases.
That allows the air on the opposing sides of the cans to push the cans towards to the area of lower pressure. We didn’t in anyway increase the air pressure on the outside of the cans so the cans were not “sucked” together, rather it was the decrease in pressure between the cans that allowed the cans to roll towards each other, they were pushed together!
We are still in need of some science fair judges so if you would like to lend a helping hand, send me a message!
The Southeast Alberta Kiwanis Science Fair is open for registration!
Do NOT miss out this year — We are looking forward to seeing all young scientists there! Visit https://www.online-registration-system.com/ab/seab/ for student, volunteer and judging registration.
More information may also be found at https://praxisscienceconnection.wordpress.com/2023/02/07/2023-southeast-alberta-kiwanis-regional-science-fair/
Also, Praxis Science Outreach still continues to do science outreach in southeastern Alberta but because of financial constraints, we are making some program changes. See https://praxisscienceconnection.wordpress.com/2023/02/09/praxis-science-outreach-society-program-changes/ for the details regarding our programs.
Patty Rooks, Senior Scientific Consultant – PRAXIS: Connecting Science and The Community of SE Alberta
Webpage: https://www.praxismedhat.com/
We also have another blog for events, activities and services that we offer at https://praxisscienceconnection.wordpress.com/ – we are involved in many community activities in SE Alberta.
If you wish to support us (Praxis Science Outreach is a registered charity) please consider doing so at https://www.canadahelps.org/en/charities/praxis-society-southeastern-alberta-sciencing-and-teching-center/?mprompt=1.
We are located at #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7
Phone: 403.527.5365 or email: praxis@praxismh.ca
Praxis Science Outreach Science Smarts Column 
Reblogged this on lochsloidh and commented:
The latest Praxis Science Smarts column in the Medicine Hat News (March 11)
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