Science Smarts: Today we are science Olympians

By Patty Rooks on October 19, 2024.

I apologize, I had to take a break this week from the Halloween these as I have some really exciting news to share. Today is an exciting day as it is the 32nd annual Praxis Family Science Olympics. I had the privilege of a sneak peak into the Education Student’s activities earlier this week and WOW am I excited to see all of the young and old scientists in our community taking part in these amazing hands on science activities.

Gather up the family and head down to Medicine Hat College in order to get challenged and sharpen your science skills. Here is an activity that is a bit similar to one you will see today just in case you cannot make it down. Let’s get started!

*Remember to ask an adult before doing this experiment.

Materials:

– Empty clear 500 mL plastic bottle

– Black permanent marker

– Nail or tack

– Water

– Baking sheet or container to catch the mess (just in case)

– Science helper

Procedure:

1. We are going to try and trick people, so on the bottle, write DO NOT OPEN on it using the permanent marker.

2. Use the thumb tack to push tiny holes in the bottle just below the letters (note: the letters should help to hide the holes).

3. Put the bottle in a sink and fill it up, the water will leak out of the holes as you do this, so you need to be fast and careful, leave the water running as you screw on the cap. Try not to squeeze the bottle it will push the water out.

4. You need to do a practice run – hold the bottle up over the sink, slowly unscrew the cap and observe what happens.

5. Refill the bottle, place on the baking tray and wait for someone to open the lid (trust me they will because it says DO NOT on it) OR get a science helper to test this out.

6. Make some observations when your science helper unscrews the lid.

7. What happens?

8. Why?

What is gong on?

I am sure you are wondering “why does water come rushing out of the holes in the bottle when the cap is loosened but NOT when it is on tight?” The scientific answer to help you out includes gravity. Gravity is always pushing down on the water in the bottle, whether the lid is on or not.

But something else must be causing the water to come rushing out of the bottle when the lid is loosened. This is where air pressure comes into play. Air pressure is pushing on the outside of the bottle from all sides when the lid is on, and the outside pressure is more than the force of gravity so most of your water stays in the bottle.

The air pressure cannot get in the bottle to push on the water inside it until the lid is loosened. Loosening up the lid even slightly is enough to let the air pressure in to push on the surface of the water, and that combined with gravity pushed the water out of the bottle.

Our annual Family Science Olympics is coming up on Saturday, October 19, 2024 from 10:00 a.m. – 3:00 p.m. at Medicine Hat College (main foyer). I hope to see you there!

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 11th Street SE, Medicine Hat, AB, T1A 1T7 Phone: 403-527-5365, email: praxis@praxismh.ca.

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