Penny Experiment

Materials: glass bottle with opening no larger than a penny, one penny, bowl of ice cold water.

Dip the penny and the threads of the bottle neck in the cold water. Put the penny over the opening of the bottle and wrap hands around the bottle until the penny jumps. The heat from your hands is transferred through conduction to the air in the bottle warming the air. This causes the air molecules to move faster which makes the penny jump.