Our robot ‘Splat’ gets very nervous around this experiment because it involves squashing metal.
There are many reasons why to crush cans; recycling aluminium, testing your strength or just for FUN (and learning some science of course!).
Try this experiment and see how the air we breathe can crush metal.
Materials
Several soft drink c
ans
Stove or hot plate
safety gloves
metal tongs
cold water
medium bowl
Remember
An adult is needed to heat the can on the stove and turn it over
Make sure to wear your gloves to protect your hands from any heat conduction
Make sure you also are wearing safety goggles to protect your eyes from any splashing hot water
Place safety goggles on.
Pour some water into a glass or plastic bowl. Add some ice cubes to make the water cold.
Place a small volume of water into the can (enough to cover the bottom), say approx. 10mL.
Turn on the hot plate and place the can on the surface to boil the water. Alternatively, get your adult to heat the can on the kitchen stove.
It must boil for a couple of minutes.
Careful Part
Hold the tongs open with your palm facing upwards.
Secure the tongs around the can and quickly & carefully lift the can turning your hand over (so that the mouth of the can is facing downwards) and place the can under the water surface.
The can implodes quickly, be ready!
Check out the ‘Wacky Science’ video of this experiment and ‘What’s Going On’ series link. They are currently ‘In Production’, so check back soon…..
 As you heat the can, the water inside boils and turns to a gas, expands and exits the can. The expanding steam pushes out most of the air inside the can.
Because the hot fast moving air inside the can pushes against the inner side of the can and prevents the outside air pressure from crushing the can. However, when you invert the can and place it into the water the following happens VERY quickly:
* The sides of the can cool down causing some of the air inside the can to condense (turn from a gas into a liquid) and form on the inner surface of the can.
* The air inside the can cools and contracts
Together both of the above cause the pressure inside the can to decrease. The air pressure outside of the can therefore pushes inwards and crushes the can.
If you would like
– more details,
– pictures of the second half of the experiment
– information on how to investigate this further
– links to everyday examples
– management hints & teaching pointers (5P Teacher develpoment program)
 ….. then why not subscribe to one of the following
(1) Crazy science Club
(2) 5P Teacher Training course called ‘Looney Lab  Classroom Creations‘
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Or you can purchase the ‘Bright Sparkes Guide’ of this demonstration only ($2.50) which has:
- HD pictures of experiment steps
- Detailed explanation of science
- Mini-challenge section (another experiment)
- Making it a ‘Scientific Method’ experience
- Graphing opportunities
- REAL links and descriptions to everyday examples of concept.
This experiment examines pressure, state changes and energy.
Pressure
Air Pressure Explain Youtube clip
Study Jams: Pressure & Weather
Detailed explanation with pictures
State Changes
Condensation information
Energy
Bitesized information on state changes
Condensation: the name given to the change of state when a vapor changes into a liquid (occurs when there is a decrease in energy)
State Change: There are 3 basic states of matter (ignoring plasma and BEC). They are solids, liquids and gases. Matter can be moved between these states if energy is added or removed.
Expand: this occurs when particles have more energy.
Contract: when particles (atoms, molecules) lose energy they slow down and get closer together.