Floating your way into Canada Day and summer

I always feel like the long weekend in July is the kickoff to summer. The weeks leading up to the end of school are hectic and extremely busy for all of us at Praxis and I suppose that once July 1 arrives we all need a well deserved break! It has been a great school year once again. I cannot thank enough the teachers, my volunteers and of course my colleagues for making this another successful year at Praxis. With that being said, I am not going to leave you high and dry this summer! Keep reading each week right here for some fun and exciting handson science experiments to keep you busy all summer long. This week let’s have some fun with a Canada Day theme. Let’s get started!

*Remember to ask an adult before doing this experiment.

Materials

- corks - string - red construction paper - toothpicks - scissors - glue - tape - lake, stream or bathtub

Procedure

1. Cut out a maple leaf shape from the red construction paper.

2. Tape the cut-out maple leaf to a toothpick. Make sure the pointy end of the toothpick is still sticking out below the bottom of your leaf.

3. Using the string, tie it securely around one cork. Make a good knot, you do not want it to fall off.

4. Take a second cork and tie it to the first cork. Using a figure eight motion back and forth tie them together.

5. Take the maple leaf and place it between the two corks. Add a little bit of glue to secure it in place. 6. Allow the glue to dry. 7. Head out to a lake, river, pool or even your bathtub and try to float your Canada Day boat.

8. Why does your boat float?

Explanation

The simplest answer to why your boat floats is buoyancy. Simply put, buoyancy is the force that causes an object to float. I think that we owe a lot of what we know about buoyancy to a man named Archimedes.

Archimedes’ principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces.

What does that mean? In your experiment, you placed your boat into the water and it sank in the water until the weight of the water it displaces is equal to its own weight. This was quite difficult to see because your boat is so light. If you were to think of how a ship floats in the ocean; as the ship is loaded with cargo, it continues to sink deeper and deeper into the water, but it is also displacing more water. This results in the magnitude of the buoyant force continually matching the weight of the ship and the cargo allowing the boat to continue to float. Patty Rooks is senior scientific consultant at PRAXIS, “Connecting Science To The Community.” Contact Praxis at praxis@praxismh.ca, www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook.