Section
Name Date
Properties of Waves
4.1
Summary
Textbook pages 134–143
Before You Read
In this section, you will find out about waves, such as water waves, sound waves, and
radio waves. On the lines below, list devices you use that make or use waves.
_______________________________________________________________________________________
Radio, speaker, boat
_______________________________________________________________________________________
◆
wavelength
✏ Mark the Text crest
Identify Details amplitude
As you skim the section, use
one colour to highlight the
trough amplitude
text that talks about parts of
a wave. Use another colour
to highlight other facts about wavelength
waves.
rest
position
What are the features of a wave?
A wave is a movement that transfers energy through matter or
space. Energy is the ability to apply a push or pull on an
object. For example, a water wave moves energy through
water. A sound wave moves energy through air. A radio wave
can move energy through space.
Because you can see water waves, it is helpful to use a
water wave to describe waves in general. You cannot see
many other kinds of waves, such as sound waves.
A water wave does not carry water along with it. Only the
energy carried by the water wave moves forward. A duck
moves up and down as a wave passes — it does not move
●
✔ Reading Check
forward.
1. What is the rest position of There are different features of waves that help you
a water wave? describe them. You can see these features labelled on the
___________________ diagram above. The dotted line represents the rest position of
the wave. This is also called the equilibrium position. For a
___________________
water wave, the rest position of the wave is where the water
___________________ would be if it were still. ●
✔
50 MHR • Section 4.1 Properties of Waves © 2006 McGraw-Hill Ryerson Limited
Section
Name Date
4.1
Summary
continued
The features of a wave are listed below.
◆ crest: the highest point of a wave
◆ trough: the lowest point of a wave
◆ wavelength: the distance from one point on a wave to the
same point on the next wave, such as from crest to crest
or from trough to trough. A wave with a long wavelength
carries less energy than a wave with a short wavelength.
◆ amplitude: the height of a wave crest from its rest
position. Amplitude is also the depth of a wave trough, as
measured from its rest position. A wave with a large
amplitude carries more energy than a wave with a small
amplitude.
How many times does a wave repeat in a period of
time?
Another important way to describe a wave is by its frequency.
You may have already heard the term frequency used to
describe radio stations or music. The frequency of a wave is ●
✔ Reading Check
the number of times it repeats in a given period of time. A 2. How is the frequency of a
repetition of a wave is also called an oscillation or vibration. wave measured?
One vibration occurs over one wavelength. ___________________
Frequency is measured in hertz. Hertz (Hz) means cycles
per second. ___________________
When the wavelength is short, the frequency is high. ___________________
When the wavelength is long, the frequency is low. ● ✔
What are the different types of waves?
You have read that sound travels by sound waves. Sound can
travel through air, water, and even solid walls. The matter a
wave travels through is called a medium. The medium can
be a solid, liquid, or gas. For example, the medium of a water
wave is water.
Not all waves need a medium. For example, visible light
waves and radio waves can travel through space where there
is no matter.
© 2006 McGraw-Hill Ryerson Limited Section 4.1 Properties of Waves • MHR 51
Name Date Vocabulary
Section 4.1
Use with textbook pages 134–136.
Features of a wave
Use the vocabulary words in the box below to label the parts of a wave.
Vocabulary
amplitude wavelength
crest rest position
trough
1. 4.
3.
5.
2.
On the line beside each term, describe the wave feature.
6. amplitude ___________________________________________________________________
_____________________________________________________________________________
7. crest ________________________________________________________________________
_____________________________________________________________________________
8. trough ______________________________________________________________________
_____________________________________________________________________________
9. wavelength __________________________________________________________________
_____________________________________________________________________________
10. rest position _________________________________________________________________
_____________________________________________________________________________
52 MHR • Section 4.1 Properties of Waves © 2006 McGraw-Hill Ryerson Limited
Analyzing
Name Date Information
Section 4.1
Use with textbook pages 134–138.
Characteristics of waves
Use the information in the graphs to answer the questions.
1. How long is the wavelength of the wave below? _____________________________
2. How large is the amplitude of the wave below? ______________________________
metres 0 metres
1 2 3 4 5 6 7
–1
–2
3. Which wave below has the smaller amplitude, A or B? _____
4. Which wave carries more energy, A or B? _____
wave A wave B
2 2
1 1
0 0
1 2 3 4 1 2 3 4
–1 –1
–2 –2
5. What is the same for waves X and Y below: amplitude, wavelength, or frequency?
__________________________________
6. Which wave has a greater frequency, X or Y? _____
7. Which wave has a longer wavelength, X or Y? _____
wave X wave Y
2 2
1 1
0 0
1 2 3 4 5 6 7 1 2 3 4 5 6 7
–1 –1
–2 –2
© 2006 McGraw-Hill Ryerson Limited Section 4.1 Properties of Waves • MHR 53
Name Date Comprehension
Section 4.1
Use with textbook pages 134–138.
True or false?
Read the statements given below. If the statement is true, write “T” on the line in
front of the sentence. If it is false, write “F,” and then rewrite the statement so it is
true.
F__ Waves transfer matter forward.
1. ____
Waves transfer energy forward, not matter.
_____________________________________________________________________________
T__ Energy is the capacity to apply a push or pull to an object.
2. ____
_____________________________________________________________________________
_____________________________________________________________________________
F__ A trough is the highest point in a wave.
3. ____
A trough is the lowest point in a wave.
_____________________________________________________________________________
F__ The wavelength is the distance from crest to trough.
4. ____
The wavelength is the distance from crest to crest or trough to trough.
_____________________________________________________________________________
T__ The amplitude of a wave is the height of a wave crest or the depth of a wave
5. ____
trough from the rest position.
_____________________________________________________________________________
_____________________________________________________________________________
F__ The larger the amplitude, the less energy is transported by the wave.
6. ____
The larger the amplitude, the more energy is transported by the wave.
_____________________________________________________________________________
_____________________________________________________________________________
F__ Amplitude is the number of motions that occur in a given time.
7. ____
Frequency, not amplitude, is the number of oscillations in a given time.
_____________________________________________________________________________
_____________________________________________________________________________
T__ Frequency is measured in units called hertz.
8. ____
_____________________________________________________________________________
F__ The wavelength of a wave increases as frequency increases.
9. ____
The wavelength of a wave decreases as frequency increases.
_____________________________________________________________________________
_____________________________________________________________________________
54 MHR • Section 4.1 Properties of Waves © 2006 McGraw-Hill Ryerson Limited
