Expansion and Contraction of Materials


•    Different materials expand or contract at different rates at different temperatures.

•    Like: Heating water can change it to steam.

•    Thus, heating a material can change it.

•    Water changes to ice on cooling.

•    Thus, cooling a material can also change it.

•    But the effect of heating is opposite to that of cooling.

•    Heating a substance can make it expand, but the amount of expansion differs in solids, liquids, and gases.

•    In general, gases expand more than liquids, and liquids expand more than solids.

•    Cooling a material contracts it.

•    James Prescott Joule studied the nature of heat, and discovered its relationship to mechanical work. He defined the unit of work as JOULE, named after him.