ScienceScene



The MAP Team

Meaningful Applications of Physical Sciences

Dr. Michael H. Suckley

Mr. Paul A. Klozik

Email: MAP@

Computer software presented at this workshop is available at our website:

▬► Science Course Support ▬► Physical Science ▬► Useful Software

The MAP Team is composed of four educators with over 100 years of exemplary science teaching between them at grade levels from second grade through college. They have worked together for over ten years to encourage and promote physics education in the elementary and middle schools in the mid-west of the United States. The M.A.P Team is certified as Operation Physics trainers. All of these educators have presented at the National, State, and local workshops. As the M.A.P. Team, they have presented over 150 workshops in Physical Science. Each of these educators has a keen interest in the improvement of science education.

The workshops are designed to:

( Enhance upper elementary and middle school teacher's understanding of physics concepts

( Provide teachers with hands-on/minds-on activities for effectively teaching these concepts to their students.

( Provide the necessary integration of physical science skills with classroom activities to promote learning.

( Provide suitable materials for teaching physical science concepts which will be utilized in the classroom.

( Develop the conceptual basis of physical science and motivational techniques to promote student learning.

( Introduce strategies to target successful student learning outcomes in science.

( Provide examples of suitable materials for teaching physical science concepts in the classroom.

( Improve the teaching of basic physical science concepts in the upper elementary and middle school grades.

Each workshop covers a traditional topic in physical science and is designed to identify important concepts and eliminate misconceptions. If you would like to learn more about the MAP team or you would like the team to develop a customized workshop for your teachers and visit your school district please contact us at: MAP@

Sound

Wave Models and the Film-a-Horn

Page

I. Naive Ideas Concerning Sound 3

II. Sound Production – Constructing Sound Devices

A. Observing Sound 4

B. Clucking Chicken 5

C. Film-A-Horn? 6

III. Building a Model Using the Characteristics of Sound

A. How Does Sound Travel?

1. Does Sound Travel Through A Vacuum? (Demo) 7

2. Do Solids Conduct Sound Better Than Air? (Activity) 8

3. Do Liquids Conduct Sound Better Than Air? (Activity) 10

B. Illustrating the Model Of Sound

1. What is a Sound Wave? 11

2. FUNdamentals of Sound 12

3. Using a Slinky to Investigate Sound

a. Wavelength, Pitch and Frequency 13

b. Loudness, energy and amplitude 14

4. Check Your Understanding of the Model 15

IV. Applying the Model of Sound

A. Using Goldwave to Analyze Sound 16

B. Using Goldwave to Analyze the Film-A-Horn 19

V. Vendor List 20

VI. Bibliography 21

I. Naive Ideas Concerning Sound

1. Sounds can be produced without using any material objects.

2. Hitting objects harder changes the pitch of the sound produced.

3. Sound waves are transverse waves that travel in exactly the same way water and light waves travel.

4. Matter moves along with water waves as the waves move through a body of water.

5. When waves interact with a solid surface, the waves are destroyed.

6. Loudness and pitch of sounds is the same thing.

7. You can see and hear a distinct event at the same moment.

8. Sounds can travel through empty space (a vacuum).

9. The sound of a train whistle changes as the train moves by because the engineer purposely changes the pitch of sound.

10. In wind instruments, the instrument itself vibrates, not the internal air column.

11. Music is strictly an art form; it has nothing to do with science.

12. In actual telephones (as opposed to tin can telephones) sounds, rather than electrical impulses, are carried through the wires.

13. Ultrasounds are extremely loud sounds.

14. Megaphones create sound.

15. Noise pollution is annoying, but it is essentially harmless.

II. Sound Production

An age old question asks: If a tree falls in a forest where there is no one to hear it, does it make a sound? To answer this question, the phenomena of sound must be defined. In the physiological sense, there are three requirements for sound:

1. A source of energy,

2. A transmitting medium for the energy,

3. A receiver to receive and decode the energy.

In the physical sense, sound is a series of energy disturbances in a material medium, not necessarily requiring a receiver or observer. Therefore, the answer to the above question depends on the definition used. In this topic, "sound" will be interpreted in its physical sense.

Sound may be specifically defined as a mechanical vibration in a material medium (solid, liquid, gas) within a frequency range approximately between 20 vibrations/sec and 20,000 vibrations /sec. These frequencies are capable of affecting the human ear (providing that its intensity is between 0 db and 120 db). Waves of frequencies lower than 20 vib/sec. are called infrasonic, and those of frequencies higher than 20,000 sec/sec. are known as ultrasonic.

Viewing Sound – A Simple Oscilloscope

The source of every sound is a vibrating body. An oscilloscope is an expensive electronic instrument which can graphically display the patterns of sound vibrations on a video screen. We can think of an oscilloscope as a device which enables us to see sound. This activity one to make a simple device that produces visual vibration patterns produced by their own voices.

Many scientific measuring instruments have dials with pointers to indicate the magnitudes of the measurements. A pointer is actually a lever that magnifies the distance that the instrument moves. Unfortunately, pointers have mass which the instrument must move. In very sensitive instruments this presents a problem, since the force that the instrument measures is too weak to overcome the mass of the pointer. The solution to the problem is a massless pointer---a beam of light referred to as a light lever! A small mirror is attached to the instrument. A beam of light is reflected off the mirror onto a screen that may be several meters distant. The beam is, in effect, a massless lever several meters long that greatly magnifies a very small movement of the instrument.

Construction:

Remove both ends of a small steel can such as a soup, nut or single serving juice can. Cut a large round balloon from the mouth, over the top and back down to the mouth. Stretch one of the two halves over one end of the can and attach it securely (see diagram).

Use sticky putty (available at stationery stores for temporarily hanging posters) or double-sided tape to fasten a small (.5 cm) mirror to the rubber midway between the center and the edge. Plastic mirror is best; many stores sell plastic mirrors for students to stick up in their lockers. These mirrors can be cut with a hacksaw or broken into small pieces with pliers (Wear Goggles). The advantage of plastic mirror is that it does not have dangerous sharp edges..

Clucking Chicken

Background: When something with a small surface like a string vibrates, it pushes a very small mass of air, resulting in a sound that is not very loud. But if the string is attached to a larger surface, forcing it to vibrate at the same frequencies as the string, the larger surface will push a larger mass of air, resulting in a louder sound. Physicists very sensibly refer to this phenomenon as forced vibration. Please understand that this is not resonance. Resonance is a special case of forced vibration in which a body is induced to vibrate at its natural frequency. Every object has one or more frequencies at which it will naturally vibrate. In this activity we will force the bottom of a plastic cup to vibrate at frequencies which are natural to a string but not to the cup bottom.

Construction: Make a small hole in the bottom of a metal can or plastic cup. Tie a small paper clip on one end of a sturdy cotton string about 70 cm long, and run the other end through the hole in the bottom of the cup (see diagram). Tie a small piece of cellulose sponge at the other end of the string. (The rectangular sponges commonly sold at supermarkets are made of cellulose.)

Procedure: Dip the sponge in water and squeeze it so that it is damp, not soggy. Hold the cup securely in one hand. With the other hand fold the sponge in half, and use it to grasp the upper part of the string tightly. While maintaining a tight grip, slide the sponge down the string with short jerking motions. The sound produced will resemble a loud, raucous chicken. By varying the manner in which the sponge is slid down the string, the sound can be made to resemble a frog or what might politely be called “rude noise.” Some students enjoy decorating their creations with felt scraps and doll eyes to resemble chicken or frog heads.

Explanation: Wetting the sponge adjusts the friction between it and the string to a level where it sticks and slips in rapid succession. This sets up an irregular mixture of vibrations in the string. Irregular vibrations result in what is commonly called noise what most people consider music results from regular vibrations. The string forces the cup bottom to vibrate at the same frequencies, thus amplifying the sound.

Further Investigation: Instead of attaching a cotton string to the cup, try various cords, wires and ribbons, or strings from violins or guitars. Instead of a damp sponge, try leather or cloth coated with beeswax or rosin. What if the string is attached to the inside of the cup instead of to the outside? Attach a spring, elastic or chain of rubber bands to the cup and pluck it. Attach a stretched wire coat hanger and bang it with a hard object. What happens if you use larger containers such as a restaurant size food can or a garbage can?

Film-a-Horn

The observation of how a Stadium horn was constructed gave rise to this inexpensive "LOUD" horn. This simple "make and take" horn will provide a high interest teaching tool for the fundamentals of sound.

Materials:

Film canister, single hole paper punch, 3/4" punch, 1" inch punch, thin plastic from a shopping bag, 4" length of 1/2" diameter PVC pipe, 3/8" bit and drill (the punches can be purchased from a hardware store)

Preparing The Materials:

1. Using the 3/4" punch; make a hole in the bottom of the 35 mm plastic film canister. To accomplish this, make sure that you set the film canister on a cutting board, place the punch on the inside of the canister, and then hit the punch with a hammer.

2. Using a single hole paper punch, punch a hole in the middle of the side of the film canister. This will become the hole that you blow into.

3. Take the cap of the film canister and punch out the center of the cap, using the 1" hole punch. This hole can also be punched out by using a piece of one-inch metal pipe.

4. Obtain a 4" long piece of 1/2 inch PVC pipe. Drill a 3/8" hole in the PVC pipe about one inch from the end of the pipe.

Assembling The Film-a-Horn

1. Insert the 1/2" PVC pipe into the 3/4" hole from the bottom of the canister. Push the PVC pipe into the film canister so that it is approximately 1/2 way into the film canister.

2. Place the cover of the film canister on the table so that the cover can be snapped onto the canister containing the PVC pipe.

3. Obtain about a 2" square piece of a plastic grocery bag and place it on top of the film canister cover.

4. Push the canister containing the PVC pipe into the plastic covered top. Once inserted the excess plastic can be trimmed off.

5. Slide the PVC pipe forward until it lightly touches the piece of the plastic grocery bag (membrane).

Note: You will know that you have done a good job if the plastic looks smooth and tight like a drumhead.

Using The Film-a-Horn

Test by blowing into the hole in the canister and moving the tube until a rich full sound is heard.

Experiment Modification

Try different types of plastic instead of the thin plastic grocery bags. Suggestions were made to try a piece of zip lock bag, a 2 mm plastic garbage bag, wax paper, aluminum foil or different types of plastic wrap. Try using a piece of 8" PVC pipe and drilling holes approximately 1" apart. This will make quite a musical instrument.

III. Building A Model Using the Characteristics of Sound

Does sound travel through a vacuum? (Demonstration)

Materials: 2 flasks, 2 rubber stoppers, 2 small bells on a stiff wire, Bunsen burner or hot plate

Students need to understand that sound is produced by vibrating objects and that as the object moves back and forth, the sound travels out from the object.

The bell will be able to be heard inside the flask at the beginning of this demonstration because there is air in the flask. Some water is then put into the flask and the flask is heated until the water boils for about a minute. The boiling forces air out of the flask because steam is produced which fills the flask. When the flask cools, the steam condenses back to water. The bell is much fainter in sound in this partially evacuated flask.

To be sure the technique is mastered, you may want to try the following procedures before demonstrating them to your class.

1. Attach a small bell to each wire and place the other end of each wire in the rubber stoppers. Adjust the wires so that each bell will hang in the center of its flask when closed.

2. Close the flasks. Shake the flasks and have the students listen to the bells.

3. Take the stopper off of one flask. Cover the bottom of the flask with water and carefully heat it over a Bunsen burner until boiling. Let the water boil for a minute or so, turn off the flame and holding the flask with a towel, immediately insert the stopper with the attached bell.

4. Let the flask cool for a minute, shake it. And try to hear the bell. Shake the unheated flask in the same way and have the students compare the sound.

5. Ask the following questions:

a. Why did you no longer hear the bell ring in the sealed flask where the water was boiled? (Because there was less air in the flask)

b. Why was the water boiled in the flask?

(To create a partial vacuum by driving out the air)

c. Can you make a general statement about sound traveling through a vacuum? (Sound does not travel through a vacuum. Sound needs a medium through which to travel)

d. Why do you think sound cannot travel through a vacuum? (Sound needs a medium to carry the vibrations)

e. Is it reasonable to be able to hear rocket exhaust or Star War sounds in outer space? EXPLAIN. (No. Sound waves do not move through empty space so you could not hear rocket exhaust or Star Wars sounds in outer space)

During discussion, emphasize that sound does not travel in a vacuum. Sound waves need a medium through which to travel. The vibrations produced by vibrating objects require a medium through which to travel. The Sound waves hit the eardrum that vibrates in response. Light waves are a different variety of waves than sound waves. Light waves do not need a medium through which to travel--they can travel through a vacuum.

To extend this demonstration, you could, if possible, procure a vacuum pump and evacuate a bottle with a bell in it. The bell will not sound when shaken. As the air is slowly allowed to enter the jar, the bell begins to be heard.

Do solids conduct sound better than air?

Materials: metal coat hanger, spoon. Thin wire, nylon fish line

1. Tie the center of a 1 meter length of string to the hock of a coat hanger.

2. PREDICT what will happen if you dangle the coat hanger on the string and hit it against the table.

3. Try hitting the coat hanger against the table. What do you OBSERVE about the result of the sound?

4. Now, PREDICT what result you will OBSERVE when you hold the ends of the string in your ears as you repeat the activity.

5. Try it. How do the sounds COMPARE when the ends of the string are held in your ears and when you did the same experiment without the string in your ears?

6. EXPLAIN what causes the sounds to be different.

7. Does air or the solid string conduct Sound better?

8. COMPARE metal wire, string and nylon fishing line as conductors of sound. First, PREDICT which one will be the best and worst conductor, then tie each of the conductors to the coat hanger in turn and listen to how well the materials conduct sound from the clanging coat hanger to your ears.

|Conductor Test |Predict - Best and Worst |Record Results |

|String | | |

|Thin Wire | | |

|Nylon Fish Line | | |

| | | |

Do Solids Conduct Sound Better Than Air? Cont.

Idea: Sounds travel better through solids than through liquids or gases.

Process skills:

Observe

Compare

Predict

Test Duration: 20 min.

Background:

Students need to know that sounds are made by vibrating objects and that they move as vibrations through matter.

Advance Preparation:

Collect the needed materials.

Students may work in pairs or in larger groups. They can pass the coat hanger string setups around and share them. In the classroom, be sure students don’t hit the coat hangers together and have the activity degenerate into a jousting match.

Management Tips:

Other objects, such as spoons, rulers or metal utensils may be substituted for the coat hangers.

Note a common naive conception among children is that air conducts sound better than solids or liquids. This activity provides a dramatic experience demonstrating superior sound conductivity of solid materials as compared to air.

Responses To Some Questions

1. Try to be sure that students understand the key comparison being made here.

2. Predictions should be verified.

3. It will make a clunking sound. The sound will not be very loud or very pleasant.

4. Many students may expect the sound to be less in volume since their ears are being plugged with their fingers.

5. The sounds are now louder and more musically pleasant. The coat hangers sound like chimes now.

6. The sound is conducted directly from the coat hanger through the solid string. More of the sound reaches your ears than when it travels through the air to your ears.

Points To Emphasize

7. Solid string.

8. Prediction answers will vary among the students. Results will depend on the actual materials experimented with. Thickness and tautness of conducting materials may be factors, as well as the densities of the conducting materials.

Be sure to emphasize that the major variable being investigated here is a comparison between movement of sound through air as compared to movement through a solid. Emphasize that denser media transmit sounds better than less dense media.

The Summary Discussion:

Try comparing longer and shorter strings. Try the activity with the coat hanger suspended from a long rubber band (little sound is transmitted because the flexible rubber band absorbs most of it and converts it into heat).

Possible Extensions:

Students may be encouraged to do some reading to discover why different substances behave differently.

Do Liquids Conduct Sound Better than Air

Have a friend take two stones into the water some distance from you. Have him bang them together in the air, and see how loud the sound is. Then have him place the stones underwater, and bang them together while your head is underwater. The sound will be much louder.

Here’s why:

Sound exists in the form of waves, and the waves travel better in water than in air. (Solids carry sound better than air as a rule. American Indians are said to have listened for distant hoof beats by placing an ear to the ground

What Is A Sound Wave? (Frequency, Pitch and Wavelength Using a Slinky)

Introduction

Imagine putting on a pair of very high-powered magnifying glasses, so that you could see the molecules of air in the small rectangular space shown in the diagram.

If the room was quiet, with little or no noticeable sound present, the air molecules in this little rectangular space it might look like:

If a very brief sound, that is a single pulse consisting of one compression and one rarefaction, was made by the Speaker on the left.

And you looked at the air molecules in the little rectangular space between the Speaker and the Listener they might now look like this:

If you looked at the air molecules in the little rectangular space a short time later they might have looked like this:

If the pulse is repeated regularly, a pattern may be created. We call this pattern of compressions and rarefactions pressure waves, or sound waves. This is what Sound waves might actually look like!

FUNdamentals of Sound

I. Characteristics Of A Wave

A. Pulse: a single disturbance in a medium.

B. Frequency: the number of occurrences of some event per unit of time. (example; the number of times the meter stick goes up and down in one minute.)

C. Amplitude: the measurement of the distance the medium moves from the zero point to the maximum displacement.( example; the distance of the very end of the meter stick - from standing still to the farthest distance away from that zero position.)

D. Wavelength: the distance along a wave front — from any starting point to the next successive starting point. (example; looking at a slinky in motion. Begin with the very beginning of a pulse to the very beginning of the next pulse.)

E. Loudness: this occurs when more and more energy is applied to the vibrating medium.

II. Components Of Light and Sound waves

A. Energy is needed to form any Light or Sound wave.

B Light waves are made by continuous succession of oscillating magnetic and electric fields. These fields travel as a wave, an EM (Electromagnetic) wave.

C. Sound waves are made by the vibrations (moving back and forth) of the particles of an object.

D. A medium is NOT needed to transport the Light energy.

E. A medium is needed to transport the Sound energy.

F. Waves are formed when energy is transported from one place to another.

III. Three Types Of Waves

A. Torsional waves when the disturbance occurs as a twisting effect in a plane that is perpendicular to the direction on the wave motion (examples: twisters, hurricanes, tornados).

B. Longitudinal waves when the disturbance occurs in the same direction of the wave motion. (examples: sound, people standing in line, cars taking off from one red light and coming to a stop at another red light.)

C. Transversal waves when the disturbance occurs at right angles to the direction of the wave motion. (examples: water, light, radio, electromagnetic.)

What Is A Sound Wave? (Frequency, Pitch and Wavelength Using a Slinky) cont.

Idea:

Waves in humans and Slinky’s model the behavior of sound waves. Sound waves are compressional or longitudinal waves. Compressions are where the matter is crowded together. Rarefactions are the uncrowded spaces in between. Although the wave may travel a large distance, the particles involved move forward and backward only a little.

Duration: 30 Min.

Process Skills: Observe, Describe, Compare

Student background: Students should be familiar with sound as vibration.

Advance preparation: None.

Management tips:

You may want to tell neighboring teachers about the human wave activity before trying it.

Responses To Some Questions:

Activity 1: A Human Wave

1. Estimates will vary. (The length of the single file line.)

2. A short distance (less than one meter). Forward and backward.

Activity: A Slinky Wave

1. Three to four meters (from one end to the other).

2. No. Only a little forward and backward.

3. In all these waves, particles push on each other, but do not move very far themselves. They are all compressional (longitudinal). That is, the compressions and rarefactions all travel away from their source along the same line as the disturbance which caused them, yet the particles involved move forward and back only a short distance as the wave passes by.

Points To Emphasize In The Summary Discussion:

Sound waves are compressional or longitudinal waves. They can move only through matter (they will not pass through a vacuum).

Only if a participant raises the question, should the fact that longitudinal waves are sometimes represented graphically as transverse wave forms for the purpose of showing their wavelength and amplitude, be mentioned at this time.

Use a series of marbles or string-suspended metal balls to show how energy can be transmitted through matter by compressional forces. A line of dominoes can also be knocked down from the center outward to demonstrate this idea (as well as the idea that sound generally travels outward from its source).

Possible Extensions:

Students can hold hands in a circle. First student squeezes hand of next person and so on. Time how long it takes pulse to return.

Loudness, Energy and Amplitude Using The Slinky

Waves can be demonstrated with a Slinky. With a partner, stretch the Slinky to a length of about 3 or 4 meters while keeping the Slinky on the floor. Have a third person tie a short (10 cm) piece of string to a single coil of the Slinky near its center. An additional piece of string should be tied about one meter from one end, and a third piece the same distance from the other end.

A. START a wave pulse by pushing rapidly on your end of the Slinky toward your partner, and then pulling rapidly back (not by whipping it).

B. OBSERVE the motion of the strings as the compression and rarefaction move down the Slinky.

C. Add more energy – make the pulse larger. Observe the affect on the wave pattern as it moves down the Slinky

D. REPEAT using various amounts of energy.

QUESTIONS

1. How far did the Slinky wave travel from you to your partner?

2. Did any part of the Slinky move very far? DESCRIBE the motion of the pieces string.

3. COMPARE sound waves from your voice human and Slinky waves.

DESCRIBE any similarities you may have noticed.

Check your Understanding the Model of Sound

1. The following drawings indicate a model of a sound. The frequency of each sound is the number of vibrations occurring each second or f = vibrations/sec. For each sound count the number of waves, determine the time for those waves and calculate the frequency of each sound.

| |Sound Model |

| |

|4. Which sounds have the same frequency but different loudness?       C and       E |

|5. Which sound is the highest frequency?       I 6. Which sound is the lowest frequency?       B |

IV. Applying The Model of Sound

Using Goldwave to Analyze Sound

1. Step 1 (a-f), provides the procedure for determining the frequency of a sound using the computer. For this example we will use a tuning fork with a known frequency of 512 Hertz. This is done just to practice the procedure. (You may want to try this on your computer)

a. Using the computer program GoldWave record the sound by:

1) Make sure GoldWave is on your computer. If it is not follow directions with disk provided. Run GoldWave and you should see:

[pic]

2) Click on 'File' and then click on NEW and you should see this window:

[pic]

3) Click on 'OK' and you should see this window:

4) Find the record button located in the Device Controls window.

[pic]

5) Produce a sound or strike the tuning fork on the mat provided. Hold the tuning fork near the microphone and click the record button.

6) After recording the sound the computer screen will look something like the following.

[pic]

b. To adjust the wave (sound) pattern so a traditional wave pattern can be seen and that has approximately ten waves are displayed on the screen select “View” and chose 1:1 view. The screen should look something like this:

If your wave pattern does not allow you to clearly see ten waves, whether the waves are to big or too small, chose the “View” and select “Zoom”. “Zoom” in or out until you can see ten or more waves.

c. Select a portion of your wave pattern, by moving the slide control, that most closely looks likes the picture. Move the mouse to the crest, (top), of a wave and click the right mouse button then move the mouse exactly ten waves and click the left mouse key. This will highlight the ten waves.

d. To find the time for one wave: (You must return to the 1:1 “View” to read your start and end times. Your ten wave marking will remain.)

1) The start or end time for our ten waves can be obtained by placing the cursor over the line marking the start or end of the ten waves. The time is indicated at the bottom of the screen (currently showing end time). Please note the time indicated is only the decimal portion of the time. The whole number portion of your time is obtained by looking at the top scale.

[pic]

i.e.: .00705 This is the start time for ten waves and is expressed in seconds.

2) The end time for our ten waves can be obtained by placing the cursor over the right end of the ten waves and record the time indicated at the bottom of the screen. In our example we found it to be: .02658 seconds. The total time for ten waves would be (end time - start time) or (.02658 sec. - .00705 sec.) which is .01953 seconds.

3) To find the time for one wave divide by ten.

.01957 sec. for ten waves / 10 = .001957 sec. per one wave

e. To find the number of waves in one second divide one second by the amount of time needed for one wave. Note: this result would be the experimental value.

waves per second = 1 sec / .001957 seconds

510.9 waves per second or 510.9 hertz.

f. Read the number on the tuning fork using this number as the theoretical value and calculate your percentage of error. For our example, the frequency is 512.0 hertz.

%Error = ((experimental value - theoretical value) x 100) / theoretical

%Error = ((510.9 hertz - 512.0 hertz) x 100 ) / 512.0 hertz

%Error = .21

Using Goldwave To Analyze the frequency of the Film-A-Horn.

Please note: The pan flute is the device that will be used to produce two sounds. The frequency of each of these sounds will then be determined. Since you need to blow on it we suggest that you wash it with soap and hot water. This procedure should ensure the safest and cleanest approach to using this device.

1. Determine the frequency of a known source of sound using the computer and the procedure you have just practiced. Record the designation written on the sound source.

2. Check your experimental frequency with the known frequency.

3. Calculate the percent of error.

4. Determine the frequency of an Unknown of sound.

a. Determine the frequency of a unknown source of sound using the computer and the procedure you have just practiced. Record the designation written on the sound source.

c. Check your experimental frequency with your instructor. If the results are close enough to the correct frequency, the instructor will provide the theoretical frequency.

d. Calculate the percent of error.

|1. Determining the frequency of a Known source of sound (480) |

|a. End time for 10 waves: |      |seconds |

|b. Start time for 10 waves: |      |seconds |

|c. Time for ten waves: |      |seconds |

|d. Time for one wave: |      |seconds |

|e. Experimental Frequency: |      |Hertz |

|f. Percentage of Error: |      |% |

|2. Determining the frequency of an the Film-A-Horn. |

| Label On the Sound Source       |

|a. End time for 10 waves: |      |seconds |

|b. Start time for 10 waves: |      |seconds |

|c. Time for ten waves: |      |seconds |

|d. Time for one wave: |      |seconds |

|e. Experimental Frequency: |      |Hertz |

|f. Theoretical Frequency: |      |Hertz |

|g. Percentage of Error: |      |% |

| |

| |

Physical Science Materials Vendor List

Operation Physics Supplier

Arbor Scientific

P.O. Box 2750

Ann Arbor, Michigan

48106-2750

1-800-367-6695

Astronomy

Learning Technologies, Inc.

Project STAR

59 Walden Street

Cambridge, MA 02140

1-800-537-8703

The best diffraction grating i've found

Chemistry

Flinn Scientific Inc.

P.O. Box 219

Batavia, IL 60510

1-708-879-6900

Discount Science Supply (Compass)

28475 Greenfield Road

Southfield, Michigan 48076

Phone: 1-800-938-4459

Fax: 1-888-258-0220

Educational Toys

Oriental Trading Company, Inc.

P.O. Box 3407

Omaha, NE 68103

1-800-228-2269

Laser glasses

KIPP Brothers, Inc.

240-242 So. Meridian St.

P.O. Box 157

Indianapolis, Indiana 46206

1-800-832-5477

Rainbow Symphony, Inc.

6860 Canby Ave. #120

Reseda, California 91335

1-818-708-8400

Holographic stuff

Rhode Island Novelty

19 Industrial Lane

Johnston, RI 02919

1-800-528-5599

U.S. Toy Company, Inc.

1227 East 119th

Grandview, MO 64030

1-800-255-6124

Electronic Kits

Chaney Electronics, Inc.

P.O. Box 4116

Scottsdale, AZ 85261

1-800-227-7312

Electronic Kits

Mouser Electronics

958 N. Main

Mansfield, TX 76063-487

1-800-346-6873

All Electronics Corp.

905 S. Vermont Av.

Los Angeles, CA 90006

1-800-826-5432

Radio Shack

See Local Stores

Lasers

Metrologic

Coles Road at Route 42

Blackwood, NJ 08012

1-609-228-6673

Laser pointers

Magnets

The Magnet Source, Inc.

607 South Gilbert

Castle Rock, CO. 80104

1-888-293-9190

Dowling Magnets

P.O. Box 1829/21600 Eighth Street

Sonoma CA 95476

1-800-624-6381

Science Stuff - General

Edmund Scientific

101 E. Gloucester Pike

Barrington, NJ 08007-1380

1-609-573-6270

Materials for making telescopes

Marlin P. Jones & Associates, Inc

P.O. Box 12685

Lake Park, Fl 33403-0685

1-800-652-6733

Natural Wonders

Nature Store

Flea Markets

Garage Sales

Bibliography

Brown, Bob. Science for you, 112 Illustrated Experiments. Pennsylvania: Tab Books Inc., 1988.

Esler, William K. Modern Physics Experiements for the High School. New York: Parker Publishing Company, Inc., 1970.

Herbert, Don. Mr. Wizard’s Science Secrets. New York: Hawthorn Books, Inc., 1965.

Joseph, Alexander, et al., Teaching High School Science: A Sourcebook for the Physical Sciences. New York: Harcourt, Brace & World, Inc., 1961.

Liem, Tik L. Invitations to Science Inquiry. California: Science Inquiry Enterprises, 1990.

Lynde, Carleton John, phd. Science Experiments with Ten - Cent Store Equipment. New Jersey: D. Van Norstrand Company, Inc., 1950.

Rudy, Lisa Jo. The Ben Franklin Book of Easy & Incredible Experiments. John Wiley & Sons, Inc., 1995.

Science Snackbook. Exploratorium Teacher Institute, 1991.

Scienceworks. Ontario: The Centennial Centre of Science and Technology, 1984.

Unesco. Scource Book for Science Teaching. France: Unesco, 1962.

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Record

Figure 4

Figure 3

Figure 2

.2-sec.

.2-sec.

.2-sec.

Slide Control

.2-sec.

Figure C 12/.20= 60

Figure B 2/.18 = 11.11

Figure A 0/0 = 0

.2-sec.

.2-sec.

.2-sec.

Figure D 8/.18 = 44.44

.2-sec.

.2-sec.

Figure F 6/.20 = 46.15

Figure E 12/..20 = 60

Figure I 16/.30 = 80

Figure H 4/.18 = 22.22

Figure G 4/.17 = 23.53

Wave Models and the Film-A-Horn

Figure 5

Figure 6

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