Crush the can demo-air pressure PDF

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Mark Good V00779907 Oct. 20/2015 EDCI 767 Science Demonstration: Can Crusher Experiment Reference: Boc k e n s t e d t ,C. , &Oa t e s , M.( 2 0 08 ) . Ea r t hs c i e nc es u c c e s s :50l e s s o np l an sf org r a d e s6 9. Ar l i n gt on , Va . :NSTAPr e s s . Possible Curriculum Context: Science 9 (The biosphere, geosphere, hydrosphere, and atmosphere

are interconnected, as matter cycles and energy flows through them); Physics 11 (Momentum and Energy can both be Conserved); Science 10 (Chemical processes require energy change as atoms are rearranged); Socials 11 (Natural processes have an impact on the landscape and the human settlement); Chemistry 11 (gas laws and pressure, PV = nRT) Materials Needed:      

1 empty Pop Can (or 2) Hot Plate Tap water Bowl Tongs or Gloves Safety Glasses

Directions: 1. 2. 3. 4. 5.

Rinse out the pop can Fill a bowl with two cups of cold tap water; ice water is even better Put two tablespoons of hot tap water in the pop can Heat the pop can on the hot plate until steam comes out of the pop can Use tongs to grab the pop can and put upside down in the cold tap water.

Sample Questions for Students:      

What is happening inside the can when it is heated up? What is going to happen when the can is put in cold water? What happens to the air pressure inside the can when heated? How does condensation effect the implosion of the can? Would the amount of water added in the can affect the implosion? Why is the phenomenon of air pressure and condensation important in daily life?

Explanation of the Effect: The implosion of the can is caused by condensation and pressure. When the water inside the can is heated up the water molecules go from a liquid state to a gas state (water vapour). This water vapour

forces the air outside of the can, producing a low air pressure system inside the can. When the can is submerged in the cold water the water vapour gets condensed from cooling. This causes a low pressure environment that results in a partial vacuum in the pop can. Since the pressure inside the pop can is less then the outside air pressure the pop can collapses, when submerged in the cold water. The cold water cools the air inside of the can very quickly and water get sucked in due to the partial vacuum, but the atmospheric pressure being greater than the inside crushes the can first to reach equilibrium. Sample Lessons: Science 9 (Atmospheric Sciences) Start the class off by talking about air pressure and how it all works. Follow-up with a short demo of the pop can implosion explain air pressure and the changes of state. This then could lead into a group discussion about air pressure and how the atmosphere works around them. If time permits have the students conduct an experiment on their own of air pressure, or research a real life problem of why air pressure is important. Geography (Socials 11 or Geography 12) A big part of geography is about atmosphere and how it is being affected by the human population, and also how it is affecting us with are everyday lives. This type of demo at the start of class could help show the students about different air pressure and how it can drastically effect humans. As an educator I would explain why the can imploded and then would ask the students to research any issue where air pressure has effected people. This could be anything from human error from cleaning a tanker and it being imploded because people weren’t educated in air pressure, and forgot to create a vacuum for the pressure to escape. They could also explore how air pressure systems work in the atmosphere and effect human’s everyday lives, for example, cyclones, hurricanes, and extreme weather events. They would have the choice of working in pairs or individual creating autonomy in their learning and practicing project based learning....