Heat and Radiant Energy
Heat
Heat is the energy that is transferred between materials that
have different temperatures.
Conduction is the transfer of energy from one material to
another.
Conduction

Example, The hot plate in a Lava Lamp heats the wax it is
touching.
Convection is the transfer of energy through a liquid or gas.
Convection

Example: The hot wax in the Lava Lamp heats the liquid
around it.
Radiation is the transfer of thermal energy across space.
Radiation

Example: The light bulb in the Lava Lamp heats the metal
plate that is above it, but not touching it.
A conductor carries or transfers heat from one object to
another. Some materials are better conductors than others.
Conductor

Examples of good conductors of heat are metals such as
copper.
An insulator is a material that is used to trap, hold or prevent
heat transfer.
Insulator
Thermal
equilibrium

Some materials that are good insulators are rubber,
wood, plastics and Styrofoam
Heat equilibrium is when materials that start out at different
temperatures reach a point where they are at the same
temperature.


Example: A pot hot water that is allowed to cool off until
it reaches the same temperature as the air around it.
The air and the water have reached the point of heat
Heat and Radiant Energy
equilibrium.
Page 208
in the
textbook
KEY TERMS:
conduction, heat, radiation, convection, heat engine, thermal
equilibrium
Include the terms from the list above to answer the following
questions:
1. What do convection, conduction and radiation all have in
common?
2. Explain the relationship between heat and thermal
energy.
3. Explain the relationship of thermal energy to the work of
a heat engine.
Answer the following questions in complete sentences:
1. What do we mean when we say that two objects are in
thermal equilibrium?
2. Explain why metal cooking pots generally have handles
made of nonmetal (wood, plastic) materials?
3. What are the differences between conduction,
convection and radiation?
4. Explain the benefit of having aluminum roofs using the
principles of radiation.
5. Describe ways insulation is designed to reduce the rate
at which heat is lost by conduction, convection and
radiation.
Heat Transfer
Definition
3 Types of Heat Transfer
Heat or energy from a warmer object to a cooler object.
1. Radiation - Heat travelling through empty space. No direct
contact.

example: Solar panels used in cars, homes and
Heat and Radiant Energy
businesses. Also pool covers which keep the heat of the
water from escaping at night.
Short Waves - High
Energy
Gamma Rays
Nuclear
explosion
Xrays
Penetrate to
Bones
Ultraviolet
(UV)
Red
Orange
Yellow
Visible Light
Green
Blue
Indigo
Violet
Infrared Light TV Remote
Microwaves
Radio Waves
TV, FM, AM
Long Wave Length - Low
Energy
2. Conduction - Heat energy that is transferred through direct
contact.

example: Pot on stove
Heat and Radiant Energy
3. Convection - Heating fluid - Transferring heat from 1 part
of fluid to another


example: boiling water.
Convection Current: is the constant flow as a fluid
continually heats, rises, cools, condenses and sinks.
This process is then repeated.