Filename: Conduction Plates

Thermodynamics

Name: Conduction Plates

Location:  L314

Equipment:  Black metal and Black Thermo Insulating plates, Ice Cubes

The two Ice Melting Blocks look similar but are composed of different materials. One block feels cold to the touch, while the other block feels slightly warm. Both blocks are at room temperature but have very different thermal conductivities and heat capacities.

Allow one or two students to touch the block, ask them which block would melt ice more quickly, or which one feels warmer. Place an ice cube on each block and watch their amazement as the “cold” block melts the ice cube within two minutes. Melting the ice cube is barely noticeable on the “warm” block. The “cold” block is aluminum and has a much greater ability to transfer heat to the ice cube or the hand.

The “warm” block is plastic, which does not conduct heat as well.

Have students touch surface around them.  Metal parts of the chair compared to wood or cloth.  Which feels colder?  Touch measure rate of heat transfer, not temperature.