Subject Area(s): Physical Science
Associated Unit: none
Associated Lesson: none
Activity Title: Waves of Sound
Image 1
ADA Description: Wave next to an ear
Caption: none
Image file name: sound_wave_ear
Source/Rights: Copyright © http://soundman-gear.com/wpcontent/uploads/2009/02/213286ear-with-sound-wave-posters.jpg
Grade Level: 7-9
Activity Dependency: none
Time Required: 1 hr, 30 min
Group Size: 6
Expendable Cost per Group: $2
Summary
Engineering Connection
Understanding the physical properties of sound is important for audio engineers who work with
sound amplification, recording, and reproduction using electronics. This activity is also relevant
to acoustical engineers, who work with noise control, ultrasound, and sonar.
Engineering Category
(1) relates science concept to engineering
Level of Inquiry
In this activity, students do six small activities to explore the properties of sound waves. It is
inquiry based in the sense that the students perform the activities, write down observations, and
then answer questions that relate what they heard/saw to the physical properties of sound.
Keywords
Sound wave, wavelength, amplitude, frequency, pitch, longitudinal wave, pressure wave,
rarefaction
Educational Standards
 State science:
Waves
4. Waves have characteristic properties that do not depend on the type of wave. As a basis for
understanding this concept:
a. Students know waves carry energy from one place to another.
b. Students know how to identify transverse and longitudinal waves in mechanical media, such
as springs and ropes, and on the earth (seismic waves).
c. Students know how to solve problems involving wavelength, frequency, and wave speed.
d. Students know sound is a longitudinal wave whose speed depends on the properties of the
medium in which it propagates.
Investigation & Experimentation
1 Scientific progress is made by asking meaningful questions and conducting careful
investigations. As a basis for understanding this concept and addressing the content in the other
four strands, students should develop their own questions and perform investigations. Students
will:
a. Select and use appropriate tools and technology (such as computer-linked probes,
spreadsheets, and graphing calculators) to perform tests, collect data, analyze relationships, and
display data.
d. Formulate explanations by using logic and evidence.
Pre-Requisite Knowledge
Students should have some background knowledge of sound waves, such as knowing that they
are longitudinal/ compression waves. They should be introduced to the parts of a wave and be
aware that they need a medium (molecules) to travel through.
Learning Objectives
After this activity, students should be able to:
 Understand that sound waves are longitudinal/ pressure waves and need a medium to travel
through.
 Waves travel the fastest through materials where molecules are less elastic (solid> liquid >
gas)
 Understand that the frequency is a measure of the energy of a wave
 Be able to solve for frequency or wavelength using the equation v = λ × f
 Understand the relationship between frequency, wavelength, and pitch
 Understand the relationship between loudness and amplitude
Materials List
Each group needs:
 Group 1: handout (attached), diagram of a longitudinal wave (from text book or one
attached)

Group 2: 4 mid-sized balloons: 2 partially filled with air (have them be the same color), 2
partially filled with water (have them be the same color).

Group 3: 3 pairs of scissors, each with a piece of string strung through both sides of the
handle.




Group 4: c-clamp, clamp pulley, 100g, 200g, 500g weights, fishing line or plastic cord, paper
cup
clamp pulley
Group 5: 3 pairs of scissor, several plastic straws (1 per student).
Group 6: Mac laptop computer with MacCRO X oscilloscope program on it (available at:
http://scopeapp.sourceforge.net/)
To share with the entire class:

Introduction / Motivation
Vocabulary / Definitions
Word
Definition
longitudinal/
A wave that vibrates in the same direction as its length.
compressional
wave
frequency
The number of waves to pass a point in a unit of time.
wavelength
The distance (measured in the direction of propagation) between two points in
the same phase in consecutive cycles of a wave
amplitude
Half the wave height.
pitch
The property of sound that varies with variation in the frequency of vibration.
medium
An intervening substance through which signals can travel, surrounding
environment (e.g., air, liquid, solid).
Procedure
Background
The teacher should be able to explain that sound waves are longitudinal (or compressional)
waves and how they differ from transverse waves. The teacher should explain what the
frequency, wavelength, pitch, and amplitude of a wave are. He/ she should also explain that
these waves require a medium to travel through, as the waves are propagated by molecules
bumping into each other.
Before the Activity
 Set up 6 group stations (1 per table group)
Group 1: handout (attached), diagram of a longitudinal wave (from text book or one
attached)
Group 2: 4 mid-sized balloons, 2 partially filled with air (have them be the same color), 2
partially filled with water (have them be the same color).
Group 3: 3 pairs of scissors, each with a piece of string strung through both sides of the
handle.
Group 4: c-clamp, clamp pulley, 100g, 200g, 500g weights, fishing line or plastic cord,
paper cup. Setup: Attach c-clamp at one end of a desk/ table & tie fishing line to the clamp.
Attach pulley clamp to other side of desk/table & string fishing line through the pulley.
Make a loop at the end of the fishing so weights can hang. Place paper cup under fishing line
on desk/ table on order to amplify sound.
Group 5: 3 pairs of scissor, several plastic straws (1 per student).
Group 6: Mac laptop computer with MacCRO X oscilloscope program on it (available at:
http://scopeapp.sourceforge.net/)
With the Students
1. Each group will start with the activity at the table that they are sitting at. After 10-15
minutes, the students in each group will rotate (so students in group 1 go to group 2, students
in group 2 go to group 3, etc.).
2. After about an hour (6 rotations), students will return to their original groups and the teacher
will lead a group discussion and ask the students for the answers on their worksheet.
Figure 1
ADA Description: Tuning fork and compressional wave
Caption: Figure 1: none
Image file name: fork_and_wave
Source/Rights: Copyright ©
http://www.qualityinformationpublishers.com/ProductImages/193.jpg
Attachments
Waves of sound worksheet
Longitudinal_wave_diagram
Safety Issues
Students should be careful when handling the scissors (be sure to keep them away from their
face).
Troubleshooting Tips
In group 3, students must stick their fingers well into their ears (like ear plugs) in order to hear
the change in pitch.
Investigating Questions
See attached student worksheet
Assessment
Pre-Activity Assessment
Title: Preliminary questions for students
Ask student the following questions:
How is sound produced? Does sound need something to move through? Why is this so? How
are sound waves different from light waves? What are the parts of a sound wave?
Activity Embedded Assessment
Title: Activity
The teacher should make sure that students are reading the directions, doing the steps of the
activity in the right order, and writing down observations on their worksheet. The teacher should
also ask questions about the concept behind each activity.
Post-Activity Assessment
Title: Class-wide Discussion
The teacher should go through each group activity and ask one group at a time what their
answers are for each activity. The teacher should clarify any confusion that the students have
and ask questions that connect each group activity to the concept it was aimed to demonstrate.
Activity Extensions
Activity Scaling
 For lower grades, this activity can be simplified by reducing the number of group activities
and allowing students more time to complete each on. All of the group activities can be
easily demonstrated by the teacher (and volunteers) in front of the class.
 For upper grades, this activity can be made more difficult by giving students more math
problems involving the formula v = λ × f (velocity = wavelength x frequency)
Additional Multimedia Support
http://videos.howstuffworks.com/hsw/6052-exploring-sound-sound-waves-video.htm
References
http://www.glenbrook.k12.il.us/gbssci/Phys/Class/sound/u11l2a.html
http://school.discoveryeducation.com/lessonplans/programs/soundwaves/
https://www.msu.edu/user/irwindeb/sound.html
http://chiron.valdosta.edu/djudd/soundlesson15.html
Other
Redirect URL
[For TE submissions only]
Owner
UCLA SEE-LA GK-12 Program, University of California, Los Angeles.
Contributors
Developers: Brittany Enzmann and Marschal Fazio. This activity was developed as part of the
UCLA Science and Engineering of the Environment of Los Angeles (SEE-LA GK-12) program
and has been classroom tested in several 9th grade Integrated Coordinates Science classes at
University High School in Los Angeles.
Copyright