Some materials are good conductors of thermal energy and some are not. We are going to compare the rate of cooling of hot water in a metal can, in a cup with thin walls, and an insulated cup. What do you think will happen: how quickly will the temperature change, and by how much? How long will your drink stay hot?

Assemble the following materials:

• shallow pan * filled with ice
• 4 thermometers *
• 3 containers:
  • metal can
  • plastic cup *
  • Styrofoam cup *
• 1 measuring cup
• clock
• hot water -- 40 to 50 C
• data sheet to print out, or use Excel

Put your graph and comments in your journal.

In addition to the printed instructions, you might review the page local materials for description of what we mean by "ice" and "hot water." The page about graphing may also be useful.
Read the procedure completely before starting

• Print out the data table (or set up the Excel page)
• Measure the temperature of the hot water
• Put a thermometer in each container
• Measure equal quantities of hot water into each container
• Immediately measure and record the starting temperature of each container (and the starting time)
• Poke three holes in the ice with your fist and place the three containers in the holes.
• One minute after the start time, record the temperature in each container. Gently stir the containers with the thermometer before making the measurement.
• Continue measuring the temperature every minute for 15 minutes. Remember to stir before measuring!
• Make a graph of the temperature in the three containers.
• Interpret the graph. What does it tell you about the right way to keep your drink hot?

Kyra and Ally are ready to start measuring

Check the box when you are done:  

Next: Finishing the first activity