Name___________________ Class______________ Date__________
Lesson 1.1: Critical Reading
Read this passage from the text and answer the questions that follow.
Mechanical Waves
A mechanical wave is a disturbance in matter that transfers energy from place to place.
A mechanical wave starts when matter is disturbed. Consider what happens when a
drop of water falls into a pond. This disturbs the water in the pond. Then the disturbance
travels outward from the drop in all directions. This is the wave. A source of energy is
needed to start a mechanical wave. In this case, the energy comes from the falling drop
of water.
The energy of a mechanical wave can travel only through matter. This matter is called
the medium (plural, media). The medium in the example just described is a liquid—the
water in the pond. But the medium of a mechanical wave can be any state of matter,
including a solid or a gas. It’s important to note that particles of matter in the medium
don’t actually travel along with the wave. Only the energy travels. The particles of the
medium just vibrate, or move back-and-forth or up-and-down in one spot, always
returning to their original positions. As the particles vibrate, they pass the energy of the
disturbance to the particles next to them, which pass the energy to the particles next to
them, and so on.
Questions
1.
Define mechanical wave.
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2.
How does a mechanical wave begin?
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3.
What is the medium of a mechanical wave?
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4.
Describe how particles of the medium move when a mechanical wave passes
through them.
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Lesson 1.1: True or False
Determine if the following statements are true or false.
_____ 1. A mechanical wave starts with a disturbance in matter.
_____ 2. Particles of matter actually travel along with a mechanical wave.
_____ 3. Transverse waves travel only through solid matter.
_____ 4. Earthquakes cause longitudinal waves.
_____ 5. In a surface wave, particles of the medium move only up and down.
_____ 6. Ocean waves crash on shore when the bottoms of the waves slow down due
to friction.
_____ 7. All waves transfer energy from one place to another.
_____ 8. All mechanical waves are either transverse or longitudinal waves.
_____ 9. Some waves do not require a medium.
_____ 10. A source of energy is needed to start a mechanical wave.
Lesson 1.1: Multiple Choice
Circle the letter of the correct choice.
1.
Types of mechanical waves include
a.
longitudinal waves.
b.
transverse waves.
c.
surface waves.
d.
all of the above
2.
The medium of a mechanical wave can be a
a.
gas.
b.
solid.
c.
liquid.
d.
any of the above
3.
The crests of a transverse wave are like the
a.
crests of a primary wave.
b.
troughs of a longitudinal wave.
c.
rarefactions of a secondary wave.
d.
compressions of a longitudinal wave.
4.
Examples of mechanical waves include all of the following except
a.
ocean waves.
b.
sound waves.
c.
waves in a rope.
d.
electromagnetic waves.
5.
Waves that an earthquake sends through rocks underground include
a.
tsunami waves.
b.
transverse waves.
c.
longitudinal waves.
d.
two of the above
6.
Which of the following statements about ocean waves is true?
a.
They travel on the surface of the water.
b.
They travel deep underwater.
c.
They are secondary waves.
d.
They are primary waves.
7.
You generate a longitudinal wave when you
a.
shake a spring up and down.
b.
shake a rope up and down.
c.
push and pull a spring.
d.
two of the above
Lesson 1.1: Matching
Match each definition with the correct term.
Definitions
_____ 1. disturbance in matter that transfers energy from place to place
_____ 2. part of a longitudinal wave where particles of the medium are spread farthest
apart
_____ 3. wave in which particles of the medium vibrate at right angles to the direction
that the wave travels
_____ 4. combined transverse and longitudinal wave
_____ 5. part of a transverse wave where particles of the medium are lowest
_____ 6. wave in which particles of the medium vibrate in the same direction that the
wave travels
_____ 7. matter through which a mechanical wave travels
Terms
a. longitudinal wave
b. trough
c. mechanical wave
d. medium
e. surface wave
f. rarefaction
g. transverse wave
Lesson 1.1: Fill in the Blank
Fill in the blank with the appropriate term.
1.
A wave in a rope is an example of a(n) __________ wave.
2.
The highest parts of a transverse wave are called __________.
3.
A(n) __________ wave is a transverse wave that occurs with earthquakes.
4.
The parts of a longitudinal wave where particles of the medium are closest
together are called __________.
5.
A(n) __________ wave is a longitudinal wave that occurs with earthquakes.
6.
Ocean waves are __________ waves.
7.
In a(n) __________ wave, particles of the medium move in a circular motion.
Lesson 1.1: Critical Writing
Thoroughly answer the question below. Use appropriate academic vocabulary and clear
and complete sentences.
Explain how the medium transfers the energy of a mechanical wave.
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Lesson 1.2: Critical Reading
Name___________________ Class______________ Date__________
Read this passage from the text and answer the questions that follow.
Wave Frequency
Imagine making transverse waves in a rope. You tie one end of the rope to a doorknob
and move the other end of the rope up and down with your hand. You can move the
rope up and down slowly or quickly. How quickly you move the rope determines the
frequency of the waves.
Wave frequency is the number of waves that pass a fixed point in a given amount of
time, such as one second. Wave frequency can be measured by counting the number of
crests or compressions that pass the point in the given time. The higher the number is,
the greater is the frequency of the wave. The SI unit for wave frequency is the hertz
(Hz), where 1 hertz equals 1 wave passing a fixed point in 1 second.
The frequency of a wave is the same as the frequency of the vibrations that caused the
wave. For example, to generate a higher-frequency wave in a rope, you must move the
rope up and down more quickly. This takes more energy, so a higher-frequency wave
has more energy than a lower-frequency wave with the same amplitude.
Questions
1.
What is wave frequency? What is the SI unit for wave frequency?
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2.
What determines the frequency of a wave?
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3.
Why does a higher-frequency wave have more energy?
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Lesson 1.2: True or False
Determine if the following statements are true or false.
_____ 1. The less compressed particles of matter become in a longitudinal wave, the
greater the wave’s amplitude.
_____ 2. The distance between two adjacent compressions of a longitudinal wave is its
wavelength.
_____ 3. The frequency of a wave is the same as the frequency of the vibrations that
caused the wave.
_____ 4. Wave speed measures the same thing as wave frequency.
_____ 5. Wavelength equals wave speed multiplied by wave frequency.
_____ 6. The resting position of particles in a longitudinal wave is where the particles
are most spread out.
_____ 7. A wave caused by a disturbance with greater energy has greater amplitude.
_____ 8. If you know the speed and wavelength of a wave, you can calculate its
frequency.
_____ 9. Waves generally travel most slowly in gases.
_____ 10. A wave with a higher frequency always has a greater speed than a wave with
a lower frequency.
Lesson 1.2: Multiple Choice
Circle the letter of the correct choice.
1.
Measures of wave size include
a.
wavelength.
b.
wave amplitude.
c.
wave frequency.
d.
two of the above
2.
The amplitude of a transverse wave is the distance between
a.
two adjacent crests.
b.
two adjacent troughs.
c.
a crest and a trough.
d.
a crest and the resting position.
3.
What is the speed of a wave that has a wavelength of 0.5 meters and a
frequency of 2 waves per second?
a.
¼ m/s
b.
1 m/s
c.
4 m/s
d.
10 m/s
4.
Wave amplitude depends on
a.
wavelength.
b.
wave speed.
c.
wave energy.
d.
wave frequency.
e.
wave energy of the original disturbance.
5.
When one wave passes a fixed point every second, the frequency of the waves
is
6.
a.
0.1 Hz.
b.
1 Hz.
c.
10 Hz.
d.
none of the above
Assume that a wave has a fixed speed. If the frequency of the wave increases,
its wavelength
a.
increases.
b.
decreases.
c.
does not change.
d.
may or may not change.
7.
The speed of waves depends on their
a.
wavelength.
b.
frequency.
c.
medium.
d.
all of the above
Lesson 1.2: Matching
Match each definition with the correct term.
Definitions
_____ 1. maximum distance the particles of a medium move from their resting position
_____ 2. number of waves that pass a fixed point in a given amount of time
_____ 3. how far a wave travels in a given amount of time
_____ 4. highest point reached by particles of the medium in a transverse wave
_____ 5. distance between two corresponding points on adjacent waves
_____ 6. location of particles of the medium in the absence of a wave
_____ 7. SI unit for wave frequency
Terms
a. hertz
b. wavelength
c. wave amplitude
d. resting position
e. wave frequency
f. crest
g. wave speed
Lesson 1.2: Fill in the Blank
Fill in the blank with the appropriate term.
1.
In a longitudinal wave, wave __________ is a measure of how compressed
particles of the medium become.
2.
Wave amplitude is determined by the __________ of the disturbance that causes
the wave.
3.
Short-wavelength waves have __________ energy than long-wavelength waves.
4.
High-frequency waves have __________ energy than low-frequency waves.
5.
Wave __________ is equal to wavelength multiplied by wave frequency.
6.
Wavelength and wave frequency have a(n) __________ relationship.
7.
Waves usually travel most rapidly through matter in the __________ state.
Lesson 1.2: Critical Writing
Name___________________ Class______________ Date________
Thoroughly answer the question below. Use appropriate academic vocabulary and clear
and complete sentences.
Explain how to measure the amplitude, wavelength, and frequency of a longitudinal
wave.
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Lesson 1.3: Critical Reading
Name___________________ Class______________ Date__________
Read this passage from the text and answer the questions that follow.
Diffraction
Did you ever notice that when you’re walking down a street, you can hear sounds
around the corners of buildings? The reason you can hear sounds around corners is
that sound waves spread out and travel around obstacles. This is called diffraction. It
also occurs when waves pass through an opening in an obstacle. All waves may be
diffracted, but it is more pronounced with some types of waves than others. For
example, sound waves spread out around corners much more than light does. That’s
why you can hear but not see around corners.
For a given type of waves, such as sound waves, how much the waves diffract depends
on two factors: the size of the obstacle or opening in the obstacle and the wavelength of
the waves.

Diffraction is minor if the length of the obstacle or opening is greater than the
wavelength.

Diffraction is major if the length of the obstacle or opening is less than the
wavelength.
Questions
1.
What is diffraction?
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2.
When does diffraction occur?
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3.
What factors determine how greatly a wave is diffracted?
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Lesson 1.3: True or False
Determine if the following statements are true or false.
_____ 1. Reflection occurs only with sound waves.
_____ 2. All reflected waves appear to be standing still.
_____ 3. The angle of incidence is always greater than the angle of reflection.
_____ 4. Diffraction is more pronounced with sound waves than light waves.
_____ 5. Wave interference occurs whenever waves enter a new medium.
_____ 6. Wave interference occurs only when a wave is reflected.
_____ 7. Light waves refract when they pass from air to water.
_____ 8. Interference occurs only when the crests of one wave overlap with the troughs
of another wave.
_____ 9. A standing wave occurs when a wave is reflected straight back from an
obstacle.
_____ 10. Wave interference always changes the speed of a wave.
Lesson 1.3: Multiple Choice
Circle the letter of the correct choice.
1.
Ways that waves may interact with matter include
a.
diffraction.
b.
destructive interference.
c.
constructive interference.
d.
all of the above
2.
Reflected waves differ from the original waves before they were reflected in their
a.
speed.
b.
direction.
c.
frequency.
d.
wavelength.
3.
4.
Refraction occurs because waves
a.
cannot travel through an obstacle such as a wall.
b.
travel at different speeds in different media.
c.
interfere with their reflected waves.
d.
none of the above
If the length of an obstacle is greater than the wavelength of a wave, you would
expect to see
a.
no diffraction.
b.
very little diffraction.
c.
a lot of diffraction.
d.
wave interference.
5.
A standing wave is a wave that
a.
is not moving.
b.
has an upright direction.
c.
is taller than other waves.
d.
appears to be standing still.
6.
A standing wave occurs because of a combination of
a.
incidence and reflection.
b.
refraction and diffraction.
c.
refraction and interference.
d.
constructive and destructive interference.
7.
Which statement about destructive interference is true?
a.
It occurs when waves pass through each other.
b.
It results in a wave with a higher frequency.
c.
It occurs when waves interact with matter.
d.
It always produces a standing wave.
Lesson 1.3: Matching
Match each definition with the correct term.
Definitions
_____ 1. change in direction of waves as they enter a new medium at an angle
_____ 2. bouncing back of waves from a barrier
_____ 3. any interaction of waves with other waves
_____ 4. situation in which crests of one wave overlap crests of another wave
_____ 5. any interaction of waves with matter
_____ 6. spreading out of waves as they pass around a barrier
_____ 7. situation in which crests of one wave overlap troughs of another wave
Terms
a. diffraction
b. wave interaction
c. reflection
d. constructive interference
e. refraction
f. destructive interference
g. wave interference
Lesson 1.3: Fill in the Blank: Fill in the blank with the appropriate term.
1.
An echo is an example of wave ___________________.
2.
We can see objects because they __________________ waves of light.
3.
You can hear sounds around the corner of a building because of wave
___________________.
4.
How much a wave is diffracted depends on the length of the obstacle and the
___________________ of the wave.
5.
6.
7.
__________________ interference increases wave amplitude.
A straight straw in a glass of water appears to be bent because of wave
__________________.
The angle with which waves strike a barrier is called the angle of ____________.
Lesson 1.3: Critical Writing
Thoroughly answer the question below. Use appropriate academic vocabulary and clear
and complete sentences.
Compare and contrast the reflection, refraction, and diffraction of waves. Include an
example of each.
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