The teacher quickly inverts the can containing boiling water into a bowl of cold water, as shown in the diagram. When the can is inverted in the cold water, the can collapses. Use ideas about particles and pressure to explain why the can collapses.

Initially the average kinetic energy of the trapped air within the can is much higher the surrounding body of air. However, when immersed in the cold water, there is a significant decrease in the average kinetic energy of the air particles due to the hot water diffusing into the cold water bath (So through a process of convection, air molecules give their kinetic energy to the body of water). Therefore, the frequency of collisions of air molecules hitting the walls of the can will decrease. This decrease in collisions results in a decrease of internal pressure. As a result of the change in pressure, this means that the atmospheric pressure is greater than the internal pressure of the can, causing it to collapse.