Answer to Question #231884 in Physics for fran006

Question

Some air is trapped inside a metal can with a tightly fitting lid. When the can is heated firmly behind a safety screen, the lid is blown off by the increased pressure inside the can. What causes the increase in pressure of the air inside the can? 

Answer 1

The increase in pressure is caused by the fact that the pressure is the force that the molecules exert on the walls of the can. The heated molecules move faster because they receive more energy, and, therefore, they exert greater force on the walls of the can.