Downingtown Area School District
Senior Scientist/Analytical Research
Rohm and Haas Company
4 through 6
3 periods of 45 minutes
Upon completion of this unit, the student will:
- conclude that sound travels by means of vibrations of matter.
- evaluate and attempt to explain the sound inquiry using prior knowledge of states of matter.
- understand how sound waves travel.
- test the relationship between frequency of vibration and perceived pitch.
Upon completion of this unit, the student will be able to:
- explore sound wave vibrations in objects.
- test and analyze how sound travels differently through vibrations passing through three different states of matter.
- test and prove
the theory that the size of an object vibrating affects the frequency
of the sound waves, and therefore changes the pitch of the sound.
- test the theory that the stiffness of an object affects the frequency of the sound waves and, therefore, the pitch of the sound.
- test and
analyze how varying the volume of water in a vessel changes the
frequency and therefore the pitch due to the length of the vibrating
- define the terms frequency and pitch.
is based on logical steps that lead to a conclusion based on testing.
Sound waves must travel through matter. Without the vibration of some
state of matter there is no sound. There is no sound in a vacuum
because there is no material to vibrate. Light waves are produced by
vibrations of electrons and are in this way similar to sound waves. The
difference is that, once produced, light waves need no matter to be
propagated through space and will travel through a vacuum. The three
states of matter that are to be tested are solid, liquid, and gas.
These states of matter have a different atomic make-up.
particles that make up a gas are widely separated and roam about the
container freely. The particles of liquids are close together but still
free to move around each other. A solid has tightly packed atomic
particles. Sound needs vibration and the more particles packed together
the greater the vibration. By changing the size, tightness, or the mass
of the vibrating object you change the frequency of the sound.
Frequency is the number of vibrations per unit of time. By changing the
sound wave's frequency you are able to change the pitch of the sound.
Columns of various lengths produce different frequencies when air is
vibrating inside them. This occurs because the length of the air column
determines the length and the sound wave that is supported. Since
wavelength and frequency are inversely proportional, the frequency and
pitch increase as the column length decreases.
Activity 1: Sound Discovery
Time period: 45 min.
Box with lid, ball,
scissors, crayons, pennies, paper cups, string, wire hangers, pencils,
slinky, tuning fork, bowl of water, any musical instruments available.
(This exploration does not depend on any one material and can be
performed with just a few of the listed materials or more materials
than are listed.)
Students will explore the sounds that objects make and try to explain what makes the sound by manipulating the object.
Teacher will begin
class by setting a box with a ball inside it on the front table and
asking students to guess what is inside. The box will have a lid so
students will probably ask you to shake the box so they are able to
guess what is inside by the sound it makes. Have students guess with
other objects as well. Scissors or crayons work well. Ask students how
they knew what the objects were. How did they get the object to make
sound? You shook it! Take students' ideas about how sound travels and
what sound is and record on the board.
Students will work in small groups and rotate around the various stations, exploring different things that create sound.
- Using a tuning
fork tapped against the heel of a shoe or a rubber mallet then placed
into water, students can see the vibrations. (NOTE: Striking the tuning
fork with a hard object might damage it and change its frequency.)
- Paper cups and
string used to create a telephone teach students about how vibration is
sent through the string when you suggest that one student pinch the
line and then let go.
- Wire hangers
and two strings tied to each side. Students put one string around each
pointer finger so that hanger is hanging down in front of them. Place
the fingers into students ears. Do Not Place String in Ears.
Have another student tap hanger with pencil. What happens when the
tapping student touches the string? Listen to the tapping without the
string near your ears.
- Use any type of
musical instrument available. Split the types of instruments up to
create separate learning stations. Wind, string, and drums should all
be placed in separate places. Circulate room. Ask students to explain
what creates the sound. Have students fill out worksheet #1 (PDF file,
see below) to guide their exploration. After the students have had time
to explore with sound, return to the board to see if students want to
add anything about sound. Students are now ready to learn that sound is
caused by vibrations. Discuss some of the objects that they explored;
what was vibrating?
Activity 2: Sound in the three forms of matter
Time period: 45 minutes
sandwich size Zip-lock bags, clean sand, water, lab sheet (copy included)
Students will test
and analyze how sound waves or vibrations travel differently through a
solid, liquid, and a gas. Students will conclude which form of matter
is the best carrier of sound waves and why.
Prepare three bags
for each group of 4 students. First bag will contain 1 1/2 cups of
clean play sand. Remove all air before sealing bag. Label this bag # 1
with a marker. Bag labeled #2 will contain 1 1/2 cups of water with all
of the air removed. Bag marked #3 will be full of air. Students work in
their groups and will use a pencil to tap table as an ear is placed on
each bag in turn. The vibrations from the tapping will travel through
the 3 different states of matter. Students will come to a consensus
about which state of matter is the best for carrying sound. Students
may record their observations on worksheet #2. Students should come to
the conclusion that sound travels through these three states of matter
differently. A solid is the best transmitter of sound, then water, and
lastly, air. Students will discuss results among their groups and,
using what they have discovered, create ways to alter the amount of
sound a guitar, a student in a classroom, and a noisy group of kids
make. See worksheet #2 continued. When the whole class gets together
have students share their ideas and creations.
Whole class discussion questions:
- Which state of matter carried sound the best?
- Which state of matter didn't carry sound well?
- Were your predictions correct?
- Why do you think you got the results you did? (Atomic particle make-up)
- How does most sound that we hear travel?
- What other experiments can we try?
- Why would Native Americans listen to the ground?
- Compare cups and long string telephone versus whisper down the lane at the same distance apart.
- At home: Talk under water in tub and compare with in the air.
- Students can create inventions for keeping sound contained or making sound louder.
Activity 3: Changing the Sound Waves Frequency
Time period: 10 to 15 min. for each of four centers
Materials: For all 4 centers
Learning Center 1. Metal spoons of various sizes with two strings tied on each spoon
Learning Center 2. Wooden boards with 6 nails pounded in as shown below, 3 similar rubber bands
Learning Center 3. 4 glass baby food jars with water in various levels from least to greatest, pencil
Learning Center 4. Wooden boards, 3 nails pounded as shown below, 3 key hole screws, fishing line
Learning Center 5. 8-12 plastic bottles (20 oz. spring water or
soda bottles work well), water in varying levels of least to greatest.
(create 2 centers from these materials.)
Students will be
divided into 6 groups, two stations will be set up for Learning Center
5 to insure small groups of no more than 5 students per group. Learning
Centers will be set up prior to class. You may wish to have 2 stations
for some of the other center activities to allow for more hands on
activity, and smaller groups. Worksheets are included, but fifth grade
students should develop their own recording method for gathering and
Stress the need for quiet, since these are listening exercises.
Learning Center 1
Students will test and analyze the theory that length changes the
frequency of the sound waves, and therefore changes the pitch of the
Large and small metal spoons with two strings tied to each spoon will
be tested by students, one at a time. The two strings will be wrapped
around the student's pointer fingers, then the fingers go into the
student's ears. Do not put string in your ear! The spoon is then
hanging between the two strings and another student will tap the spoon.
Students will repeat the steps with all the sizes of spoons. Students
will compare the pitch of the various sizes of spoons and come to a
consensus. Is the pitch of the smaller spoon higher or lower than the
larger spoon? Students can fill out worksheet #4.
Learning Center 2
Students will be able to test and analyze how length of a vibrating
object affects the frequency of the sound waves, and therefore changes
prep ahead: Pound nails into board as shown. There should be three sets
of nails of ascending length on the board. Using 3 identical rubber
bands, cut once to open. Tie one end to underneath of each nail head.
Stretch each so that the thickness of the rubber band is the same for
all 3 lengths. You may need to experiment with the tightness. Students
will pluck each band, listening to the pitch of each. Students should
come to a consensus about size and pitch. This should be linked to a
similar statement regarding frequency. Students can record data on the
#4 worksheet provided.
Learning Center 3
Students will test and analyze how various levels of water affect the pitch and therefore the frequency of sound waves.
Teacher prep ahead: Fill jars with various amounts of water. Students
will tap glasses below water line to determine how volume/mass affects
pitch. Students will come up with a statement regarding volume of water
and frequency. Students can use worksheet provided to record findings.
Circulate the room to assure student understanding. What is vibrating?
Learning Center 4
Students will test and analyze how tightness changes frequency and
pitch of sound produced when fishing line is plucked. (a string
instrument can also be used)
Prep: A board with 3 large headed nails pounded into it as shown to the
right; and 3 key holed screws, screwed into the other end so that
fishing line can be tied to the nails and wrapped around the key hole
screws. Teachers may want to set each line at varying tightness and tie
off to quicken the process. The screws should be able to be turned to
tighten and loosen. Students will test the fishing line in 3 varying
tightnesses, by plucking each string. Students should come to a
conclusion about how tightness affects pitch. Students may record a
statement on the worksheet provided in this document. Question students
as to how they think tightness affects the sound waves.
Learning Center 5
Students will use columns of air in differing lengths to determine how length of a vibrating object effects pitch.
Teacher Prep: Take up to 6 plastic bottles and fill with water in
ascending amounts. This will provide students with many different
pitches to compare. Students will need to practice blowing over the top
of the bottles to create a clear tone. Students who have wind
instrument experience will be a big help in demonstrating the proper
technique. Students need to be mindful of what is creating the sound.
Vibrating columns of air at different lengths produce different
This experiment is courtesy of