Summary The students will learn how to make a basic musical instrument and how to modify it to get different loudness and pitches.

Transcription

1 Partnerships Implementing Engineering Education Sound: 4.D.3B Rubber Band Banjo Grade Level 4 Sessions 50 minutes Seasonality N/A Instructional Mode(s) Whole class Team Size 2 WPS Benchmarks 04.SC.PS SC.IS SC.IS SC.TE SC.TE.06 MA Frameworks 3-5.PS IS IS TE TE.2.3 Key Words Pitch, Sound, Loudness, 8-note scale Summary The students will learn how to make a basic musical instrument and how to modify it to get different loudness and pitches. Learning Objectives 2002 Worcester Public Schools (WPS) Benchmarks for Grade 4 04.SC.PS.01 Design and construct a simple sound-producing device to predict, demonstrate, and describe the properties of loudness and pitch of sound. 04.SC.IS.01 Ask questions and make predictions that can be tested 04.SC.IS.04 Conduct multiple trials to test a prediction. Compare the results of an investigation or experiment with the prediction. 04.SC.TE.01 Identify materials used to accomplish a design ask based on specific property (e.g., weight, strength, hardness, and flexibility). 04.SC.TE.06 Identify relevant design features (e.g., size, shape, weight) for building a prototype of a solution to a given problem. 1 of 7

2 Additional Learning Objectives Partnerships Implementing Engineering Education PS.11 Recognize that sound is produced by vibrating objects and requires a medium through which to travel. Relate the rate of vibration to the pitch of the sound IS.1 Ask questions and make predictions that can be tested IS.4 Conduct multiple trials to test a prediction. Compare the results of an investigation or experiment with the prediction TE.1.1 Identify materials used to accomplish a design task based on a specific property, i.e., weight, strength, hardness, and flexibility TE.2.3 Identify relevant design features (e.g., size, shape, weight) for building a prototype of a solution to a given problem. Required Background Knowledge Essential Questions 1. How can I modify the loudness and pitch of my rubber band banjo? Introduction / Motivation * The day before the lesson is taught ask the students to bring in a shoe box top from home. Ask the students if they know how a guitar works. Procedure The instructor will: 1. Review sound and pitch. (10 minutes) 2. Remind students that this is an engineering activity and the steps they take must be recorded in their notebooks. 3. Split the class into groups of two students: (40 minutes) i. Hand out materials to each group ii. Write the numbers 1-8 on the inside of the lid. Use a ruler to space them evenly across the whole lid. (See attachment: Banjo) 2 of 7

3 Partnerships Implementing Engineering Education iii. Put four thick rubber bands around the lid over the numbers 1 through 4. iv. Put four thin rubber bands around the other half of the lid over the numbers 5 through 8. v. Have the students answer the following questions in their science notebook: 1. Pluck one of the rubber bands. How can you make a soft sound? Louder sound? 2. Which bands (thick or thin) make higher sounds? (the highness and lowness of a sound is pitch) 3. Press down a rubber band halfway across the lid. Pluck the piece of the rubber band closest to you. What happens to the pitch when you shorten the rubber band? 4. How does tightening the band have an affect on pitch? Loosening the band? (you can do this by pulling the band near the edge of the cover. 5. Try to make an 8-note scale. (Do-Re-Mi-Fa-So-La-Ti-Do) (pluck lightly so the strings stay tuned) 6. Once tuned, have them play See if they can figure out what song it is. (Row-Row-Row your boat) Materials List Materials per class Amount Location N/A N/A N/A Materials per group Amount Location Shoe Box Lid 1 Shoe Store Thick Rubber Bands 4 Office Supply Store Thin Rubber Bands 4 Office Supply Store 3 of 7

4 Partnerships Implementing Engineering Education Vocabulary with Definitions (in alphabetical order) 1. Frequency How fast something (like a sound producing rubber band) vibrates. The faster the vibration, the higher the frequency note Scale The basic notes of Do-Re-Mi-Fa-So-La-Ti-Do. Assessment / Evaluation of Students The instructor may assess the students in any/all of the following manners: 1. Grade based on participation 2. Collect notebooks and assess if the questions had been answered correctly Lesson Extensions Attachments 1. Rubber Band Banjo Background 2. Banjo 3. Stringed Instruments Troubleshooting Tips Safety Issues Additional Resources Key Words Sound, Pitch, Loudness, 8-note scale 4 of 7

5 Rubber Band Banjo Background Preparation and Background: The tightness, thickness, and length of a rubber band (or string) all affect its pitch. Sounds are higher with taut, thin, short strings; they are lower with looser, thicker, or longer strings on any stringed instrument. The tension of each rubber band may be adjusted by pulling up or down at the side of the lid. Friction between the band and the lid hold the band in place for a while. However, the band will need to be strummed or plucked gently. A sturdy lid is preferable to a flimsy one that bows in the middle. Generalization: The length, tension and thickness all affect the pitch of the vibrating string/rubber band. Comments: Parts 5 and 6 can be somewhat difficult and not all students may be able to understand/complete them. These are more like extra credit problems for groups that excel in sound and waves. Sources Science in Elementary Education 7 th Edition, Peter C. Gega, 1994

6 Banjo Sources Science in Elementary Education 7 th Edition, Peter C. Gega, 1994

7 Stringed Instruments Teacher s note: Please do not teach this word for word. Read and understand it yourself and only teach what you feel is necessary to get the lesson and vocabulary across to your students. In a stringed instrument, pitch depends on the length, tightness, and thickness of the strings. Shortening a string causes faster vibrations, raising pitch. Lengthening it has an opposite effect. Tightening a string also increases pitch, whereas lessening tension decreases it. A thick string vibrates more slowly than a thin one, and so produces a lower sound. Why do different instruments- a violin and a cello, for instance- play a note at the same pitch yet sound different? This is because of the quality of tone (timbre) produced by these instruments. Most vibrations include more than just simple, back-and-forth movements along a strings entire length. Although there is a fundamental vibration that covers the basic pitch, other strings vibrate at faster frequencies. The combinations of vibrations are different with each string and with various stringed instruments. Together they produce tones of distinctly recognizable quality. Sources Science in Elementary Education 7 th Edition, Peter C. Gega, 1994