GRADE: Fourth

CONTENT STANDARD: Physical Science

CONTENT TOPIC: Energy/Light/Heat/Sound

CONCEPT: Sound, heat, and light have many properties.

CONTENT OBJECTIVE: 4C1.00 To understand the properties of sound

INSTRUCTIONAL OBJECTIVES: The learner will:

1.01 determine that sound travels through vibration.
1.02 relate that sound vibrations move through matter as sound waves.
1.03 determine that sound is a form of energy.
1.04 determine that sound waves move more quickly through solids.
1.05 relate that sound waves do not travel in a vacuum.
1.06 define loudness or softness of sound as volume.
1.07 define highness or lowness of sound as pitch.
1.08 define number of times an object vibrates in one second as frequency.
1.09 an echo is a reflected sound wave.
1.10 demonstrate the formation of an echo.
1.11 Identify surfaces that absorb or reflect sound waves.

I. Definition of sound
II. Sound waves
III. Define property of volume
IV. Definition of pitch
V. Definition of frequency
VI. Definition of echo
VII. Surfaces that absorb or reflect sound waves

TN COMPONENT OF SCIENCE: Habits of Mind

TN GOAL:

To enable students to demonstrate ways of thinking and acting inherent on the practice of science; and to exhibit an awareness of the historical and cultural contributions to the enterprise of science.

3.6 CREATIVE ENTERPRISE - Creativity contributes to the process of science through ideas and inventions.

3.6a Imagination plays an integral role in science.

BENCHMARK: Science engages the creative nature of all people

BENCHMARK: The process of invention is driven by need and individual insight.

TIME REQUIRED:

Classroom Connector One - three to five instructional periods; Classroom Connector Two - 30 to 45 minutes

This Classroom Connector addresses Instructional Objectives 1.01 through 1.09.

MATERIALS:

Paper clips; string; bicycle wheel; combs; pieces of small, thin, firm cardboard; index cards

Close your eyes and be completely still. Listen (teacher plays a sound tape), tell me what you heard. (response) All these are different SOUNDS. Today we begin our study of sound. You will learn what causes sound, what the properties of sound are, and how sound waves can be reflected or absorbed.

Sounds are caused by vibrations. When an object vibrates, it pushes on molecules of air causing these molecules to bump other molecules passing the motion on. This is how sound travels through air. These sound WAVES thus travel through air and other matter. (Have students simulate a sound wave by standing shoulder to shoulder about 20 cm apart in a long row. Push the first person gently to start wave motion.) You can feel these vibrations by placing your fingers against your throat while you talk. You can see these vibrations if you strum any kind of taut string. (show instrument) Sound is a form of energy because it causes matter to move. Sound travels through air this is why we could hear the sounds earlier when we closed our eyes and listened quietly. Sound travels through liquids. Can you hear sounds while swimming under water? Sure you can! Sound travels most rapidly through solids. Sounds can be loud or soft. This loudness or softness is its volume. The more energy, the louder the sound. Sound travels through matter by vibration. One molecule pushes to the next and so on. We will experiment with sound traveling through matter.

We will use paper cups and string to make a string telephone. (Have a student put a cup to his/her ear and stretch a long piece of string tightly. Have someone say numbers softly into string telephone. The other person will repeat what is heard. Say the same thing softly without using string telephone.)

String carries sound better than air. Put your ear against the wall and have one student tap the wall from some distance away with eraser end of a pencil. As the tapping continues, lift your ear away from wall so that sound reaches you through the air. Which is louder - through the air or the wall. Why? (Molecules are closer together in a solid. They can bump each other more easily to carry sound from one molecule to another.)

Sounds also differ in pitch. Pitch is the highness or lowness of a sound. An object vibrating very fast makes high-pitched sounds. Lower pitched sounds are made by objects vibrating more slowly. The number of times per second an object vibrates is its frequency. An object vibrating many times a second has high frequency. An object vibrating only a few times a second has a low frequency.

(If you have students at your school who ride bikes, then you might want to do the set outside using an actual bicycle wheel.) Today we will learn about how vibration of sound waves determines if you will hear a high or low sound. We are going to use a bicycle and a piece of cardboard to do this.

If we took a piece of cardboard and fastened it to a bicycle wheel so that it touched the spokes, when the bike was ridden fast, the cardboard would vibrate rapidly and we would hear a high pitch. The slower the bicycle wheel turned, the slower the cardboard would have vibrated and the pitch would have been lower. (Write PITCH on the board.) Pitch is the highness or lowness of a sound. (Have students write this definition on an index card.) Different pitches are made by different vibrations. High pitched sounds are made by vibrations that go back and forth very quickly. Low pitched sounds are made by slower vibrations. If you want the sound to be louder, you add more force. To make a guitar louder, you would hit the strings harder. To make a piano louder, you would strike the keys harder. When you add more force to something that is vibrating, you have AMPLIFIED the sound. Loud sounds differ from soft sounds in their amplitude.

(Give each child an inexpensive pocket comb and a thin, firm piece of cardboard. Hold the comb in one hand and the cardboard in the other. Run the cardboard across the comb - first slowly, then quickly.) When you rub the cardboard quickly, how does it sound? (response) When you rub the cardboard slowly, how does it sound? (response)

Sound does travel through matter. To prove this, I will arrange four objects on a table in front of the class. I will let you name each object. Then you will rank them according to which one sound travels through fastest. Write your responses on your paper. (Teacher might use steel bar, brick, water, empty jar for air. Check rankings. Have students complete the following:)
1. Sound does travel through matter _____. (True or False)

2. Sound travels through _____. (Vibrations)

3. Loudness or softness is _____.(Volume)

4. Highness or lowness is _____.(Pitch)

Sing "Old MacDonald" or any familiar song which you think the students will enjoy singing. After singing it in the usual manner one time, try singing the song at a different pitch. Tell your class that when you raise your hand, it means to raise the pitch. If you lower your hand, this means lower the pitch. Record the song and play it back. Stress raising and lowering the pitch - not the volume.

(Construct musical instruments for a concert and/or invite a group of musicians from the junior high or high school band to play for the class. Instruct the musicians to play pieces with a variety of pitches. Students sitting in the classroom audience can raise their arms up or down as they hear the pitch change. The group could also demonstrate change in volume or amplitude.)

(Accent On Science, Teachers Edition by Sund-Adams-Hackett-Moyer. This sheet gives instructions on how to make ruler sounds. It also asks specific pitch related questions about the ruler sounds.)

This Classroom Connector addresses Instructional Objectives 1.10 and1.11.)

MATERIALS:

Echo handout sheet (This can be made up by using information in INSTRUCTION), seashells, paper and pencil for sketching

Class, today we will go to the gym. You need to enter silently and then sit down in the middle of the gym floor. We will do some things in the gym that will help us learn about sound waves. (Teacher should yell out something that will get their attention, such as "Forty fourth graders fought," or "fabulous". The children should notice that the words repeat back and forth. Get the group quiet again.) Listen as I say "Hello." What do you hear? ("Hello" repeated over and over) Today we're going to learn about sounds that bounce off of materials.

Sounds are bouncing off the walls in this gym. These bouncing sound waves are called echoes. I am going to give you a handout on WHAT IS AN ECHO? Echoes are sound waves that bounce back to your ears. If you stand about 55 steps away from a brick wall on an empty playground and shout, the sound waves of your voice bounce off the wall and return to you. You hear them as an echo. Out why do they bounce back? (The brick reflects the sound waves) Sound waves are reflected or bounced off by some form of matter. An echo is one kind of reflected sound. The sound waves bounce off an object and are reflected back to the source. Smooth or hard surfaces (walls and floor of a gym) reflect sound best. Soft, or rough surfaces curtains) tend to absorb sound waves rather than reflect them.

Remember that sound waves are carried by molecules in the air. Air molecules are loosely packed. But the molecules in a brick wall are very close together. So, when the air molecules strike the wall, they bounce off. And the sound waves they carry are sent back as an echo.

Let's repeat as a group the first line of our handout. ECHOES are sound waves that bounce back to our ears.

(Each child will walk to the center of the gym floor and shout his or her name. The remainder of the class will listen as the echoes ring throughout the building.)

(Ask children to think about other places besides the gym and the playground where they have hear echoes before. Have them sketch these places and label them. At the end of 10 minutes, each child should show his or her sketch and discuss why he or she thinks an echo is made there.)

(Write on the chalkboard: Definition - When sound waves strike a solid surface, such as a cliff or steep hillside, some distance away, we often hear them a second time as they are reflected back to us. We call such sound an echo. Students should read this aloud with the teacher.)

(Teacher-made work sheet with drawings of places on it. Students should "X" if they think an echo will occur there.)

(Allow students to hold a variety of seashells up to their ears. Tell them that some people think they hear the roar of the ocean inside but what they are actually hearing is an echo. The shape of the shell makes it pick up any little sound. The sound bounces back and forth until it sounds like a low roar.)

This is the time this file has been accessed since 07/01/97.

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