Pop cans, tents and bridges!

Miss Laverty 2012***worksheets, experiments and lesson

adapted from the Edmonton Public curriculum book***

Happy Monday!

1. Hand out the workbooks2. Grab a copy of today's worksheet 3. Sit down and show me that you are ready to

“move some pop cans”

Magic Moving Pop Cans

• Challenge: use only a straw and your breath to make the two pop cans move towards each other

• Materials: two pop cans and one straw

• Work with a partner to try different ways to get the cans to move towards each other. Describe your strategies

• What were your strategies?• What worked best?• Diagram

Magic Moving Pop Cans

Magic Moving Pop Cans

• Results: – The easiest way to get the cans to move towards

each other was to blow through the center of the cans with the drinking straw

Magic Moving Pop Cans

• Inferences:– When we blow through the center of the two cans, the

air is moving quickly– Bernoulli’s principle states that the faster air moves,

the less pressure it exerts on surfaces over which it is passing

– By reducing the air pressure between the cans, the air pressure on the other side of the cans is now greater than the air in between them

– This causes the cans to be pushed together by the regular air pressure of the room

Magic Moving Pop Cans

• Real life examples:– Wind chimes

London Bridge is falling down

• Question: how does the speed of air affect the pressure it exerts?

• Materials: paper • Procedure

1. Fold a sheet of paper in half to create a tent shape2. Predict what will happen when you blow through the tent. 3. Stand the tent up on the table and hold the corners

between your thumbs and forefingers 4. Blow through the tent 5. Record observations

Paper Tents and Tunnels

• Record a before diagram and a during diagram • Try the tent shape and the tunnel shape

Paper Tents and Tunnels

• Inferences– Blowing through the tent produces faster moving

air– Faster moving air creates a low pressure area

inside the tent– The higher pressure of the air on the outside of

the tent causes the sides to bend in

Paper Tents and Tunnels

Real life example:• “Galloping Gertie”: a suspension bridge from

the 1940s couldn’t handle air blowing under and over the bridge

• http://www.youtube.com/watch?v=j-zczJXSxnw

Group Work

• Stay on task • Respect the learning of everyone• Follow instructions