What's new

There’s no such thing as suction

By , 25 July 2013

This may surprise you, but there’s no such thing as suction. In this week’s video we look at what creates ‘suction’; air flow and areas of high and low pressure.

Video transcript available here.

Imagining the ‘power’ of the air around us is difficult, but the ways you can demonstrate it are quite cool. When the ruler is broken, it is the pressure of air above the newspaper that holds the ruler down. There is about one kilogram of pressure above each square centimetre of newspaper. On a typical broadsheet this equates to around 5,000 kg pressing on the ruler.

How many square centimetres do you think cover the garbage bag? If you consider that there is about one kilogram of pressure for each square centimetre of the garbage bag covering the person inside. Trust me, it’s certainly not comfortable. It sucks!

Teacher’s notes with curriculum links available here.


Leave a Reply

By posting a comment you are agreeing to the Double Helix commenting guidelines.

This site uses Akismet to reduce spam. Learn how your comment data is processed.