Waves

Page
1

Slide 1

Waves: sound & light

Waves carry energy from one place to another

© 2000 Microsoft Clip Gallery

Slide 2

Nature of waves

Waves (Def.) – A wave is a disturbance that transfers energy.

Medium – Substance or region through which a wave is transmitted.

Speed of Waves – Depends on the properties of the medium.

© 2000 Microsoft Clip Gallery

Slide 3

SAMPLE LESSON: Light & the Electromagnetic Spectrum

By D. L. Power

Revised 1/20/01

© 2000 Microsoft Clip Gallery

Slide 4

Albert Einstein

Slide 5

Light: What Is It?

Light Energy

Atoms

As atoms absorb energy, electrons jump out to a higher energy level.

Electrons release light when falling down to the lower energy level.

Photons - bundles/packets of energy released when the electrons fall.

Light: Stream of Photons

© 2000 Microsoft Clip Gallery

© 2000 Microsoft Clip Gallery

Slide 6

Electromagnetic Waves

Speed in Vacuum

300,000 km/sec

186,000 mi/sec

Speed in Other Materials

Slower in Air, Water, Glass

© 2000 Microsoft Clip Gallery

Slide 7

Transverse Waves

Energy is perpendicular to direction of motion

Moving photon creates electric & magnetic field

Light has BOTH Electric & Magnetic fields at right angles!

© 2000 Microsoft Clip Gallery

Slide 8

Electromagnetic Spectrum

© 2000 Microsoft Clip Gallery

Slide 9

Electromagnetic Spectrum

Visible Spectrum – Light we can see

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

Largest to Smallest Wavelength.

Slide 10

Electromagnetic Spectrum

Invisible Spectrum

Radio Waves

Def. – Longest wavelength & lowest frequency.

Uses – Radio & T.V. broadcasting.

© 2000 Microsoft Clip Gallery

Slide 11

Modulating Radio Waves

Modulation - variation of amplitude or frequency when waves are broadcast

AM – amplitude modulation