Mechanical Waves, Sound & the Electromagnetic Spectrum
Chapter 11 & 12
Nam e:____________________________ Date: ____
Period: _____
Part I: Mechanical Waves (pg318-325)
1. How are mechanical waves produced?
2. What is a medium?
3. Which of the following are mediums through which waves can travel? Circle all that apply.
Rock
Water
Air
4. A transverse wave causes the medium to vibrate at ____________________ angles, or perpendicular, to the
direction of the wave.
5. Draw perpendicular lines.
6. What is an example of a transverse wave?
7. A longitudinal wave is a wave in which the vibration of the medium is ____________________________________ to
the direction the wave travels.
8. Draw parallel lines.
9. What is an example of a transverse wave?
10. What is a compression?
11. What is a rarefaction?
12. Label the compressions & rarefactions of each wave. Are these longitudinal or transverse waves?
13. What is a surface wave? Give an example.
14. Label the mechanical waves in the diagram below.
15. Label the parts of the wave (Fig 2):
a._______________________________
b. ______________________________
a.
c. ______________________________
c.
d. ______________________________
16. What is the definition for wavelength?
17. What is the definition for frequency?
18. What is the definition for amplitude?
19. What is the relationship between wavelength and frequency?
20. How are the amplitude and pitch related?
d.
Fig 2
b.
.
Part II: Wave Speed (pg 323-324)
1. The speed of an object equals the ________________________ traveled
divide by the _______________________.
2. Calculate the speed of a car that travels 70 miles in one hour. Show your work.
3. What is the equation for the speed of a wave?
4. What are the units for wavelength (check out Math Skills pg 324)? ____________________________
5. What are the units for frequency (cycles per second)? ____________________________
6. What happens to the wave speed if you increase the frequency?
7. The musical note A above middle C has a frequency of 440 Hz. If the speed of sound is known to be 350
m/s, what is the wavelength of this note? Show your work!
8. One of the largest organ pipes is in the auditorium organ in the convention hall in Atlantic City, New
Jersey. The pipe is 38.6 ft long and produces a sound with a wavelength of about 10.6 m. If the speed of
sound in air is 346 m/s, what is the frequency of this sound
Part III: The Behavior of Waves (pg 326-329)
1. What is reflection? Give an example.
2. What is refraction? Give an example. (pg 327 & 366)
3. What is diffraction? Give an example.
4. What is interference? Give an example.
5. Label the types of interference in the pictures below
Part IV: Sound & Hearing (332-335)
1. The image to the right shows sound waves
traveling from the girl’s mouth to the guy’s
ear. Are sound waves longitudinal or
transverse waves?
2. Through which media do waves travel the
fastest? Why is this?
3. Through which media do waves travel the
slowest? Why is this?
4. Sound intensity levels are measured in units called decibels. The decibel scale is based on powers of?
5. A 0 decibel sound can just barely be heard. A 20 decibel sound has __________ times more energy per
second than a 0 decibel sound.
6. Pitch is the frequency of a sound. High-frequency sounds have a ____________________ pitch and low –
frequency sounds have a _____________________ pitch.
7. What important applications is ultrasound used for?
8. _____ When an automobile moves towards a listener, the sound of its horn seems relatively
a. low pitched
b. high pitched
c. normal
9. _____ When the automobile moves away from the listener, its horn seems
a. low pitched
b. high pitched
c. normal
10. _____ The changed pitch of the Doppler effect is due to changes in
a. wave speed
b. wave frequency
11. True / False: A moving wave source does not affect the frequency of the wave encountered by the
observer.
12. True / False: A higher frequency results when a wave source moves towards an observer.
13. Two fire trucks with sirens on speed towards and away from an observer as shown below.
a) Which truck produces a higher than normal siren frequency?
b) Which truck produces a lower than normal siren frequency?
14. Label the parts of the ear
15. Use the terms in the box to fill in the paragraph
air
bones
brain
cochlea
electrical
impulses
vibrations
Something vibrates to produce a sound. Sound travels through _______________ to the ear. When the
vibrations reach the eardrum they are transferred to the small _______________ called the hammer, anvil
and stirrup. The bones pass the vibrations to the _______________ . This contains sense cells which change
the vibrations to _______________ signals called impulses. The auditory nerve takes the _______________ to the
brain. We hear the sound when the message reaches the _______________ .
16. Use the pictures below to answer the following questions
A
B
C
D
E
Which two sounds have the same loudness or volume? __________________________
Which sound wave has the highest frequency? ________________________________
Which sound wave has the lowest frequency? _________________________________
Which sound wave has the lowest pitch? ____________________________________
Which sound wave is twice as loud as the sound in D? __________________________
Part V: Electromagnetic waves (pg 350-367)
1. A diagram below shows the electromagnetic spectrum. What type of mechanical wave is an
electromagnetic wave, longitudinal or transverse?
2. When is an electromagnetic wave produced?
3. Label the electric field and magnetic field of the electromagnetic below.
4. Do electromagnetic waves need a medium?
5. What is the speed of light in a vacuum (or empty space)?
6. In a vacuum, all electromagnetic waves travel at the same speed. But not all electromagnetic waves are
the same. Electromagnetic waves vary in wavelength and frequency. Solve the following problems. Use
the equation: Speed = wavelength x frequency
speed (c)= 3.0 x 10 8 m/s
a. A radio station broadcasts a radio wave with a wavelength of 3.0 meters. What is the frequency
of the wave?
b. The radio wave of a particular AM radio station vibrates 680,000 times per second. What is the
wavelength of the wave?
7. When white light hits a prism what happens?
8. Look at the electromagnetic
spectrum
 ________ Radio waves
 ________ Infrared
 ________ Visible light
 ________ Ultra Violet
 ________ X-rays
 ________ Gamma rays
9. What is polarization?
A. longest wavelength, shortest frequency, television, microwave & radar
B. have the shortest wavelength & highest frequency, used in the medical
field to kill cancer cells and make pictures of the brain, and in industrial
situations as an inspection tool
C. used in medicine, industry & transportation to make pictures of the
inside of solid objects
D. waves that you can see, ROYGBIV
E. has a higher frequency than violet light, used in health & medicine and
in agriculture
F. used as a source of heat (heat lamps) and to discover areas of heat
differences (rescue), you cannot see