Science Smarts: Air pressure

By Patty Rooks on November 22, 2025.

Well, what a week, it seems as if something goes wrong, it is a steady stream of disasters! A plumbing malfunction is what inspired this week’s article. I had to pull out a tool I have not used in quite some time. If the truth was to be told, I did not even know where I put it as it has been that long since I used it! Let’s investigate!

*Remember to ask an adult before doing this experiment.

Materials

– Toilet plunger (NEW)

– Petroleum jelly

– Hardcover books (of various sizes and weights)

– Runner bands

Procedure

1. Prepare the books you are going to use.

2. Place the rubber bands around the books so they are tightly wrapped up like a present. Use a few to secure the covers to the entire book BUT leave a space in the middle between the rubber bands large enough for the plunger to fit into.

3. Line the books up on the floor – make sure the floor is s smooth surface, not carpeted.

4. Rub petroleum jelly all along the edge of the plunger (this is why it should be new).

5. Push the plunger as hard as you can on the book, then lift it straight up.

6. Do you have enough FORCE to lift it up?

7. What is the heaviest book you can lift up?

What is going on?

A plunger is a tool that gets its power from AIR PRESSURE. When you push that plunger onto the hard surface, it “squishes” or pushes all of the air out and in turn creates a VACUUM. The vacuum is created because there is virtually no air left in the plunger.

BUT on the outside, of the plunger, there is a ton of AIR PRESSURE which is pushing very hard. This is the force that allows the books to be lifted up by the plunger. Trust me, I know it is a hard concept because we cannot see the air pressure pushing, we have to experiment in order to see the results.

Save the date for the southeastern Alberta Regional Science Fair. It will take place on Saturday, March 21, 2026. Mark your calendars and start thinking of what you will do. I cannot wait to see all of the students from all over southeastern Alberta there.

As well, do not forget that Praxis is here to support classrooms and schools with their in house science fairs!

Patty Rooks, senior scientific consultant Praxis Science Outreach Society. Praxis has moved! We are very fortunate to be located in the Community Futures Entre Corp Building at #202 556 Fourth St. SE, Medicine Hat, Alberta, T1A 0K8. For all your science needs, please email praxis@praxismh.ca.

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