Heat Transfer Activity: Keep the Heat
Subject Area:
Thermal Mechanics
 
Age or Grade:
9th through 12th
 
Estimated Length:
2-3 class periods
 
Prerequisite knowledge/skills:     
  1. •understand how to read an algebraic expression
  2. •what the Greek letter "delta" (Δ) means
 
Description of New Content:
Students will test how well various materials resist the flow of thermal energy by constructing a small hot-box
 
students will learn:
  1. •that there is a relationship between heat flow and temperature difference
  2. •what the "R-value" of thermal insulators means
  3. •that different materials have a different resistance to heat flow
 
Materials Needed:
  1. •see lab procedures
  2. •2 liter soda bottle
  3. •box tape
  4. •knife to punch hole
  5. •water source connected to hose
 
Procedure
 
Make a leaky water container to demonstrate the Water flow analogy handout. With the soda bottle, punch two holes near the bottom of the bottle at the same distance from the bottom. Make one hole obviously larger than the other. You can now use the tape as a crude valve to let water flow through the either hole.
 
Go through the Water flow analogy handout and demonstrate the concept using the soda bottle. Have a discussion with the class of how the water analogy translates into heat flow.
 
Stress to students that it only takes a heat "pressure," or temperature difference to have heat flow across a boundary.
 
Give students the lab procedures and equipment.
 
Evaluation:
see lab procedures
 
As a class, discuss what students saw happen during the lab. If students understand how heat flows through an insulator, the should be able to tell you what conditions would cause maximum heat flow and what conditions would cause least heat flow.
Extensions     Let students test more materials to line the boxes with such as aluminum foil, paper, plastic, small balloons filled with a small amount of air, etc.
 
References:
Water flow analogy handout