Build your own barometer

Transcript

Speaker 1: Hey guys!

Speaker 2: Hey guys!

Speaker 1: We're here with the Science.gc.ca Team to bring you cool and exciting science experiments that you and your friends can try at home. Every experiment we provide you can be found online at science.gc.ca and our seven activity books.

Today we'll be exploring atmospheric pressure. So, let's get started.

Speaker 2: What you're going to need is a mug, some glue, an elastic band, balloons, an index card, adhesive tape, and a straw.

So, the first thing you're going to want to do is cut a piece of the balloon, large enough to cover the top of the glass, or soup can. Now, stretch the balloon tightly over the jar, and secure it in place with an elastic band. Now, cut the straw so that it's about 10 cm long, and trim one end into a point. With the sharpened end pointing out, lay the straw on the balloon with the flat end at, about, the center of the balloon. Glue the straw in place. Now, draw reference marks on one of the long edges of the card at, roughly, half centimeter intervals. Tape the opposite, or unmarked, side of the card to the jar, with the narrow end of the rectangular card extending above the jar top, and the marked edges just behind the straw.

So, what's going to happen?

Speaker 1: So, the pieces of the balloon that are stretched across the jar will act as a membrane. When the air pressure outside the jar rises, it will push down on the balloon, forcing it slightly into the jar. This, in turn, will cause the end of the straw to rise. Similarly, when the air pressure outside falls, the air pressure in the jar will be greater than the air pressure around it, forcing the balloon to expand slightly. This will cause the end of the straw to drop.

Speaker 2: So, that's all the time we have, but we hope you learned something cool about the changes in air pressure. If you liked the video, be sure to give it a thumbs up, and share with all your friends. Stay tuned for our next experiment with science.gc.ca. Thanks for watching.

Speaker 1: Bye guys.

Date modified: