1. Log into the iRespond system.

2. What do the following three items have in common?

A zipperA sharkA comb

a. Identify the characteristics of electromagnetic and mechanical waves.

b. Describe how the behavior of light waves is manipulated causing reflection, refraction diffraction, and absorption.

c. Explain how the human eye sees objects and colors in terms of wavelengths.

d. Describe how the behavior of waves is affected by medium (such as air, water, solids).

What are some everyday uses of electromagnetic radiation (or waves)?

Aa. Produced by the motion of electrically charged particles moving back and forth.

A.The charged particles are surrounded by:

i. Electric fields

ii.Magnetic fields

B.Transverse waves

C. Do not require a medium

d. All electromagnetic waves Travel at 300,000,000 m/s in a vacuum

Nothing travels faster than the speed of light!

e. Travels slower when passing through a medium

A.Particle nature

i. Travels in bundles of energy

ii. Bundles act like small particles

iii.Called photons

A.Wave nature

i. All electromagnetic waves travel at the same speed

ii. Frequency and wavelength are used to classify the waves in the electromagnetic spectrum

The electromagnetic spectrum is the complete range of electromagnetic waves placed in order of increasing frequency.

ELECTROMAGNETICSPECTRUM

As the frequency increases:

a.Wavelength decreasesb.Photon penetrating energy increases

A.Uses: Communication (telephones, pagers, radio transmission, global positioning system

B.Long wavelength and Low frequency

C.Lowest Photon energy

A.Uses: Cooking, cellular phones, radar

B.Long wavelength and Low frequency

C.Lower Photon energy

A.Wavelength is only a little longer than visible light

B.Uses – Remote controls, thermal energy transfer (radiant energy) including night vision, infrared photography, locating tumors

(Remember all living object give off infrared radiation.)

A.Only wavelengths that can be detected by the human eye

B.Use – allow humans to see

A.Higher frequency and shorter wavelength than visible radiation

B.Uses– Produces vitamin D in human skin and can be used to kill bacteria and viruses (sterilize equipment)

C.Warning! – too much can cause skin cancer; Ozone in the atmosphere blocks it

A.Higher frequency and photon energy – greater penetrating power

B.Uses: X-ray pictures; rays will penetrate soft matter like skin and muscle, but it is absorbed by the harder bones

A.Highest frequency -- greater penetrating power

B.Uses: destroy human cells and can be used to kill cancerous cells

Get ready!

What produces electromagnetic

radiation?

What type of wave is electromagnetic

radiation?

Name a wave that can travel faster than

electromagnetic radiation?

What is a photon?

Name the longest electromagnetic

wave.

What name do we give to all the electromagnetic waves arranged from longest wavelength to shortest wavelength?

Name electromagnetic wave used to see a child in

a burning house.