Waves

1
Waves Electromagnetic Radiation

• Chapter 6

Great Idea Whenever an electrically charged
object is accelerated, it produces
electromagnetic radiationwaves of energy that
travel at the speed of light
2
Chapter Outline

• The Nature of Waves
• The Electromagnetic Wave
• The Electromagnetic Spectrum

3
The Nature of Waves
4
Energy Transfer by Waves

• Wave
• A traveling disturbance
• Properties of Waves
• Wavelength
• Frequency
• Velocity
• Amplitude

5
The Relationship Among Wavelength, Frequency, and
Velocity

• Velocity of a wave
• Equation

6
The Two Kinds of Waves Transverse and
Longitudinal

• Transverse
• Motion is perpendicular to wave direction
• Longitudinal
• Motion is same direction as wave

7
Interference

• Interference
• Constructive Interference
• Act together
• Destructive Interference
• Cancellation

8
The Electromagnetic Wave
9
The Anatomy of the Electromagnetic Wave

• Point A
• Maximum strength, but decreasing
• Point B
• Minimum strength, but increasing
• Electromagnetic waves continue through internal
  mechanisms and transfer energy as they travel

10
Light The Energy of Electromagnetic Waves

• Speed of Light
• All electromagnetic waves have same velocity
• c300,000km/s
• Energy
• Higher frequencyblue color
• Lower frequencyred color

11
The Doppler Effect

• Doppler Effect
• Wave motion is independent of its source
• If source moves, frequency appears to change

12
Transmission, Absorption, and Scattering

• Transmission
• Wave passes through matter
• Absorption
• Wave energy are absorbed
• Scattering
• Waves absorbed and reemitted
• Diffuse scattering
• Reflection

13
The Electromagnetic Spectrum
14
The Electromagnetic Spectrum

• Maxwells equations
• Predicted more waves
• Hertz
• Radio
• waves

15
Radio Waves Microwaves

• Radio Waves
• Range kilohertz to hundreds of megahertz
• Longest waves
• Microwaves
• Range 1mm-1m

16
Infrared Radiation

• Infrared Radiation
• Range 1mm-1µ
• All warm objects emit radiation

17
Visible Light

• Visible Light
• Range 700nm-400nm
• Colors
• Slices of electromagnetic spectrum

18
Ultraviolet Radiation

• Ultraviolet Radiation
• Range 400nm-100nm
• Shorter wavelengthmore energy
• Damage to cells
• Fluorescence

19
X-rays Gamma Rays

• X-rays
• Range 100nm-0.1nm
• High-frequency
• Medicine
• Gamma Rays
• Range 0.1nm (10-10m)-10-12m
• Highest frequency
• Medicine
• Astronomy