Chapter 16 WavesSection 1 What are waves?
I. Waves – rhythmic disturbances that carry energy without carrying
matter
II. Mechanical Waves
A. Waves which use matter – called medium – to transfer energy from
particle to particle
1. Ripples on a pond
2. Sound waves – travel through solids, liquids, and gases
B. Kinds of mechanical waves
1. Transverse waves – matter in the medium moves up and down or
back and forth at right angles to the direction the wave travels
a. Crests – high points
b. Troughs – low points
2. Compressional waves – matter in the medium moves forward and
backward along the same direction the wave travels
– sound waves
III. Electromagnetic Waves
A. Travel through space where there is no matter
B. Types
1. Radio 5. Ultraviolet
2. Microwaves 6. X-rays
3. Infrared 7. Gamma
4. Visible light
Section 2 Wave Properties
I. Amplitude
A. One half the distance between a crest and a trough
B. The greater the amplitude, the more energy the wave carries
II. Wavelength
A. Transverse wave – the distance from one crest to the next or one
trough to the next
B. Compressional wave – the distance from the center of one
compression to the center of the next compression
C. Frequency – the number of wavelengths that pass a given point in 1s
1. Hertz – the unit of frequency
2. The faster the vibration , the higher the frequency
D. Wave speed
1. Light travels at 300 million m/s in air
2. Sound travels at 340 m/s in air
E. Wave speed equation:
wave speed (in m/s) = frequency (in Hz) x wavelength (m)
v = f λ
Chapter 18 Electromagnetic Waves
Section 2 The Electromagnetic Spectrum
I. Electromagnetic Waves
A. Classifying Electromagnetic Waves
1. Electromagnetic spectrum – formed from electromagnetic waves
with different
a. Frequencies
b. Wavelengths
2. Waves in different parts of the spectrum have different names
3. All waves travel at the same speed through empty space
a. Speed of light
b. 299,792,458 m/s
186,000 miles per second
671 million miles per hour
c. Can be slowed due to medium and temperature
II. Radio Waves
A. Have lowest frequency of all electromagnetic waves
B. Carry least amount of energy
C. TV signals, AM and FM radio signals
D. Microwaves
1. Higher frequency and shorter wavelength than waves in home
home radio
2. Cause water molecules in food to vibrate faster
III. Infrared Waves – felt as heat
IV. Visible Light
A. Electromagnetic waves you can detect with your eyes
B. Most objects don’t give off light, they reflect it
V. Ultraviolet Radiation
A. More energy than visible light
B. Can damage molecules that make up living cells
VI. X Rays and Gamma Rays
A. X rays – enough energy to go through skin and muscle
B. Gamma rays
1. Highest frequency, most energy
2. Produced by the changes in nuclei of atoms
3. Can be dangerous
I. Waves – rhythmic disturbances that carry energy without carrying
matter
II. Mechanical Waves
A. Waves which use matter – called medium – to transfer energy from
particle to particle
1. Ripples on a pond
2. Sound waves – travel through solids, liquids, and gases
B. Kinds of mechanical waves
1. Transverse waves – matter in the medium moves up and down or
back and forth at right angles to the direction the wave travels
a. Crests – high points
b. Troughs – low points
2. Compressional waves – matter in the medium moves forward and
backward along the same direction the wave travels
– sound waves
III. Electromagnetic Waves
A. Travel through space where there is no matter
B. Types
1. Radio 5. Ultraviolet
2. Microwaves 6. X-rays
3. Infrared 7. Gamma
4. Visible light
Section 2 Wave Properties
I. Amplitude
A. One half the distance between a crest and a trough
B. The greater the amplitude, the more energy the wave carries
II. Wavelength
A. Transverse wave – the distance from one crest to the next or one
trough to the next
B. Compressional wave – the distance from the center of one
compression to the center of the next compression
C. Frequency – the number of wavelengths that pass a given point in 1s
1. Hertz – the unit of frequency
2. The faster the vibration , the higher the frequency
D. Wave speed
1. Light travels at 300 million m/s in air
2. Sound travels at 340 m/s in air
E. Wave speed equation:
wave speed (in m/s) = frequency (in Hz) x wavelength (m)
v = f λ
Chapter 18 Electromagnetic Waves
Section 2 The Electromagnetic Spectrum
I. Electromagnetic Waves
A. Classifying Electromagnetic Waves
1. Electromagnetic spectrum – formed from electromagnetic waves
with different
a. Frequencies
b. Wavelengths
2. Waves in different parts of the spectrum have different names
3. All waves travel at the same speed through empty space
a. Speed of light
b. 299,792,458 m/s
186,000 miles per second
671 million miles per hour
c. Can be slowed due to medium and temperature
II. Radio Waves
A. Have lowest frequency of all electromagnetic waves
B. Carry least amount of energy
C. TV signals, AM and FM radio signals
D. Microwaves
1. Higher frequency and shorter wavelength than waves in home
home radio
2. Cause water molecules in food to vibrate faster
III. Infrared Waves – felt as heat
IV. Visible Light
A. Electromagnetic waves you can detect with your eyes
B. Most objects don’t give off light, they reflect it
V. Ultraviolet Radiation
A. More energy than visible light
B. Can damage molecules that make up living cells
VI. X Rays and Gamma Rays
A. X rays – enough energy to go through skin and muscle
B. Gamma rays
1. Highest frequency, most energy
2. Produced by the changes in nuclei of atoms
3. Can be dangerous