Light Energy

Crest -Highest point of a wave.

Crest

Trough

Trough - low point of a wave.

Wavelength

The distance between one crest to the next crest or the distance between one trough to the next.

wavelength

Amplitude

The height of the wave that indicates how much energy is carried by the wave.

Types of Waves

Transverse Waves

Waves move up and down in patterns that have high points called peaks.

The vibration is across the direction of the wave.

Compression Wave

Energy travels back and forth in the same direction that the wave is moving.

Sound travels in a compression wave.

Electromagnetic

A special type of transverse wave; energy that travels through space at 300,000,000 meters per second

(Speed of Light)

Electromagnetic Spectrum

Arrangement of electromagnetic waves by wavelengths and frequencies.

Spans from short wavelength, high frequency, high energy waves to long wavelength, low frequency, low energy waves.

Light is part of the electromagnetic spectrum.

The electromagnetic spectrum is a wave of energies with different frequencies.

Light is a form of energy that travels in electromagnetic waves.

It is the fastest mode of travel.

Light can travel through EMPTY space.

Electromagnetic SpectrumVisible Spectrum – Light we can see

Roy G. Biv – Acronym for Red, Orange, Yellow, Green, Blue, Indigo, & Violet.Largest to Smallest Wavelength

Your teeth absorb more of the X-ray energy than the rest of the mouth. The amounts of energy in different places make a picture of your teeth on the film.

Invisible Spectrum (Cont.)X-Rays

Def. - EM waves that are shorter than UV rays. Uses: Medicine – Bones absorb

x-rays; soft tissue does not. Lead absorbs X-rays.

Short Wavelength Microwave

Invisible Spectrum (Cont.)Infrared Rays

Def – Light rays with longer wavelength than red light.Uses: Cooking, Medicine, T.V. remote controls

The ultraviolet rays in sunlight can harm the skin.

Invisible spectrum (cont.).Ultraviolet rays.

Def. –EM waves with frequencies slightly higher than visible lightUses: food processing & hospitals to kill germs’ cellsHelps your body use vitamin D.

Invisible spectrum (cont.)Gamma rays

Def. Highest frequency EM waves; Shortest wavelength. They come from outer space. Uses: cancer treatment.

Radio waves are not sound waves, but you can use a radio to hear music and voices.The radio and its speakers convert radio waves to an audio signal and then into sound waves.

Invisible SpectrumRadio Waves

Def. – Longest wavelength & lowest frequency.Uses – Radio & T.V. broadcasting.

Waves carry different amounts of energy.

Light and Sound Energy are both forms of wave energy.

How are light and sound energy different?

Light waves can travel through empty space, but sound waves need a medium to carry them.

Microwaves are higher in energy than radio waves because they have a higher frequency.

What do all waves have in common?

All waves carry energy.