What Is Heat?
The fan inside this CPU is one example of why heat is so important to engineering and the design of engineered systems, as well as our everyday lives.Copyright (left) 2008 atteSmythe, Flickr (CC); (right) 2010 Portland Fire and Rescue, City of Portland, OR http://www.flickr.com/photos/attesmythe/2926574819/ http://www.portlandoregon.gov/fire/article/310471?archive=2010-07
Students learn about the definition of heat as a form of energy and how it exists in everyday life. They learn about the three types of heat transfer—conduction, convection and radiation—as well as the connection between heat and insulation. Their learning is aided by teacher-led class demonstrations on thermal energy and conduction. A PowerPoint® presentation and quiz are provided. This prepares students for the associated activity in which they experiment with and measure what they learned in the lesson by designing and testing insulated bottles.
Understanding heat transfer is essential knowledge for the engineering of mechanical, chemical and biological systems. Design of internal combustion engines, air conditioning and heating systems, chemical and biological reactors and even clothing technology requires an understanding of heat transfer. Design of insulating materials for homes, buildings and even beverage containers also requires an understanding of heat transfer.
After this lesson, students should be able to:
- Explain that heat is the flow of energy from hot materials to cold materials.
- Describe that molecules in a material begin to vibrate (or move) more quickly when the material is heated.
- Identify conduction as heat transfer within and between solids.
- Identify convection as heat transfer involving gases or liquids.
- Identify radiation as heat transfer carried by little packets of energy that can travel through almost any material—even empty space.
- List examples of each type of heat transfer.