Science with Samantha: Crushing Cans With Air Pressure
- A Bowl of Ice Water
- Pop Can
- Stove Top or Bunsen Burner
- Tongs or Heat Resistant Gloves
- Fill the clean and empty can with enough water to cover the base fo the can.
- Place the can on the heat until the water in the can is boiling or until you hear a sizzling sound
- Grab the can with heat resistant gloves or tongs and flip the can with the open mouth into the ice water.
- The can should crush! (If it didn’t work the first time make sure the can is completely facing upside down and that the water is boiling!)
By bringing the water in the can to a boil, steam displaces the air within the can. When the pop can is quickly placed into the cold water a vacuum seal is created around the can that doesn’t allow any air into our out of the can. But when the cold water changes the state of the gas back to a liquid the pressure outside and inside the can becomes unbalanced. This discrepancy between the outside and the inside of the can leads to a net inward force that results in crushing of the can!
Some Questions To Prompt The Activity
- What is a force?
- Does force need to be balanced?
- What happens when the force inside and outside a can is no longer balanced?