1. Electromagnetic Energy

2. Electromagnetic Energy
Energy is the ability to do work.
Electromagnetic energy is the energy radiated by all matter in the universe that is not at absolute zero.
Absolute zero is the temperature at which particles of matter (atoms) exhibit no motion (-273°C or 0 Kelvin).
Electromagnetic energy moves in the form of transverse waves. A transverse wave vibrates 90° to the direction in which the wave is moving.
crest
trough
A wavelength is the distance between any two corresponding points (crest or trough) on a cycle.

3. Electromagnetic Spectrum
Types of Electromagnetic Energy
Types of electromagnetic energy are determined by their wavelength
Visible light is the only form of electromagnetic energy that can be seen.
Wavelengths shorter than visible light are known as short–wave electromagnetic energy.
Wavelengths longer than visible light are known as long–wave electromagnetic energy.
RT = Pg. 14
Electromagnetic Spectrum

4. Interactions Between Electromagnetic Energy and the Environment
SCATTERED: waves refracted and/or reflected in many directions as they pass through a material
ABSORPTION: waves taken into a material
REFRACTION: waves bend as they pass through a material
REFLECTION: waves bounce off material
TRANSMITTED: waves pass through a material

5. Energy Absorption vs. Surface Properties
The characteristics of a surface can determine how much electromagnetic energy is absorbed.
Dark surfaces tend to absorb more electromagnetic energy than light surfaces.
Light surfaces tend to reflect electromagnetic energy.
Rough surfaces tend to absorb more electromagnetic energy than smooth surfaces.
Rough surfaces have a greater surface area for electromagnetic energy to be absorbed by.

6. Energy Absorption vs. Surface Properties
Surfaces that are good absorbers of electromagnetic energy tend to be good radiators of electromagnetic energy.
-- Dark clothes will absorb more electromagnetic energy and radiate more energy.
-- The boy will heat up more quickly.
-- Light colored clothing will reflect most electromagnetic energy.
-- Not much energy to be radiated.
-- The boy will not heat up as quickly.