Can Crush Experiment

WHAT IS THE AIR PRESSURE?

Atmospheric or air pressure is a force applied on a surface by the air above because of the influence of the gravity. Gravity is pulling down the air molecules and they are pressing their weight on top of the Earth’s surface.

The pressure is highest at the sea level, where there is the highest density of those air molecules. As the altitude increases, the atmospheric pressure drops.

Besides altitude, the amount of humidity is an important influence on the air pressure. Water molecules in the air weight less than the oxygen (and other gas molecules) so as the air becomes more humid, it’s lighter and therefore the pressure is lower.

At the sea level, air pressure affecting our body is approximately 15 tons! But that pressure won’t crush us since there is also an inner pressure of the equal size so they nullify each other.

MATERIALS NEEDED FOR THE CAN CRUSH EXPERIMENT:

Empty can
Bowl with the cold water
Spoon
Tongs
Heater or stove

INSTRUCTIONS ON DOING THE CAN CRUSH EXPERIMENT:

Watch the video at the beginning of the article for step by step instructions or continue reading.

Put one spoon of water into the empty can.
Put can on the heater and heat it until the water boils. You will notice the steam rising from the can.
Use the thongs to move can from the heater and quickly flip it into the cold water (upside down)
You will instantly hear loud pop and the can will crush because of the pressure difference

SCIENCE BEHIND THE CAN CRUSH EXPERIMENT

By heating up our can, we boiled the water inside it. The process of boiling turned the water into the vapor and forced the molecules of air out from the can.

When we put the can in the cold water, we suddenly cooled it. That cooling caused the water vapor in the can to condense, creating a partial vacuum. Because of that, the pressure outside of the can became much greater than the pressure inside, and that pressure difference crushed the can.