Name: Design Musical Instruments Engineer s Journal ANSWER GUIDE

Transcription

1 Name: Design Musical Instruments Engineer s Journal ANSWER GUIDE YOUR GRAND ENGINEERING DESIGN CHALLENGE: Design and build a musical instrument that can play at least three different notes and be part of a classroom band, using common craft materials and LEGO pieces.

2 How can we make different sounds? DESIGN A MUSICAL INSTRUMENT PART 1 TODAY S EXPLORATION QUESTION: How do instruments make sounds? In the space below, write AND draw your answer to this question. If you don t know, take a guess. Instruments make sounds by vibrating and making the air around them vibrate. 1-1

3 How can we make different sounds? GRAND ENGINEERING DESIGN CHALLENGE: Build a musical instrument that can play at least three different notes. a) What science ideas do you already know that will help you with your design? Vibrations are the source of sound. b) What science ideas do you need to learn to help you with your design? What makes different vibrations sound different? 1-2

4 How can we make different sounds? TODAY S ENGINEERING CHALLENGE: Your challenge is to make three different notes using a plastic cup and a plastic spoon. STEP 1. Explore the different sounds you can make using a plastic cup and plastic spoon. STEP 2. In the chart below, record your observations. STEP 3. Explain which parts of each object you used to make the sound (column one). STEP 4. Explain what you action you took to cause the sound (column two). STEP 5. Describe the sound that you made (column three). What OBJECT (noun) made the sound? What ACTION (verb) caused the sound? What words would you use to DESCRIBE the sound to someone? EXAMPLE: The bottom of the cup and the handle of the spoon EXAMPLE: Hard tapping on the bottom of the cup Loud and rhythmic, like a drum The curved part of the spoon and curved part of the cup The tip of the spoon and the hollow inside of the cup Scraping the spoon around the cup Moving the spoon back and forth, from side to side of the inside of the cup Scratchy and continuous, like a soft scraping noise A quiet, repetitive sound with echoes 1-3

5 How can we make sturdy instrument frames? DESIGN A MUSICAL INSTRUMENT PART 2 TODAY S EXPLORATION QUESTION: Most musical instruments are made out of metal, wood, or plastic. Why are instruments made out of these materials instead of paper or cloth? In the space below, write AND draw your answer to this question. If you don t know, take a guess. Instruments are made out of metal, wood, and plastic because those materials are harder and stronger than paper or cloth. Metal, wood, and plastic are strong enough to hold very tight strings and drum heads without bending or breaking. Metal, wood, and plastic also last longer than paper and cloth. 2-1

6 What makes a drum make a sound? DESIGN A MUSICAL INSTRUMENT PART 3 TODAY S EXPLORATION QUESTION: How does a drum make its sound? How do you know? In the space below, write AND draw your answer to this question. If you don t know, take a guess. The membrane of the drum vibrates (moves back and forth) after it is hit. The vibrating membrane makes the nearby air vibrate (move back and forth). The back-and-forth vibrations of the air are what make the sound. 3-1

7 What makes a drum make a sound? TODAY S ENGINEERING CHALLENGE: Design and build a miniature drum using LEGO pieces and a stretched balloon. Make observations of your drum so that you have an answer to this question: How does the drum make a sound that our ears can hear? STEP 1. Find the sturdy triangle that you built in lesson 2. STEP 2. While one partner holds the triangle, the second partner should stretch a balloon over it. The first partner should push connector pegs through the edges of the balloon and into the holes on the triangle s beams. STEP 3. Test your drum. Do you like its sound? Does it stay together? If not, change your design and build a new drum. Remember that re-designing and re-building are always a part of engineering. STEP 4. In this step, you will investigate how your drum makes sounds. Your teacher will sprinkle some grains of sugar onto your drum head. 3-2

8 PART A. As you play your drum SOFTLY, listen to the sound and watch your drum. What happens to the sugar when you play your drum SOFTLY? Record your observations here. WHAT WORDS WOULD YOU USE TO DESCRIBE WHAT YOU HEAR AND SEE? DRAWING OF WHAT HAPPENS HEAR: Soft thumping sound. SEE: The sugar bounces up and down a few times after the drum is hit. Sugar stays towards the center. What makes a drum make a sound? PART B. As you play your drum HARD, listen to the sound and watch your drum. What happens to the sugar when you play your drum HARD? Record your observations here. WHAT WORDS WOULD YOU USE TO DESCRIBE WHAT YOU HEAR AND SEE? DRAWING OF WHAT HAPPENS HEAR: Louder thumping noise. _ SEE: The drum vibrates a lot, and the sugar bounces and spreads to the edges of the balloon. 3-3

9 PART C. What does the sugar show you about how your drum makes a sound? Write at least two complete sentences to describe what the sugar helps you notice. The sugar moves further away from the center when it is hit harder. This shows that the amplitude of the vibrations of the balloon is larger when it is hit harder. 3-4

10 What do sound vibrations travel through? DESIGN A MUSICAL INSTRUMENT PART 4 TODAY S EXPLORATION QUESTION: How does a musical instrument s sound get from the instrument to our ears? In the space below, write AND draw your answer to this question. If you don t know, take a guess. The sound from the instrument vibrates columns of air, which eventually vibrate the air just outside our ears. 4-1

11 What do sound vibrations travel through? TODAY S SCIENCE DRAWING ASSIGNMENT: Pick one of the following mediums: solid, gas, or liquid. Draw a picture AND write sentences to explain how sound travels through that medium. When a sound is made, the sound source vibrates columns of air. Vibrating columns cause other columns of air to vibrate until vibrating air reaches our ears. 4-2

12 What do sound vibrations travel through? TODAY S CHALLENGE: Construct a new kind of instrument called a pan pipe. The pan pipe is an example of a wind instrument, which is any instrument whose vibrations are created by moving air. Pan Pipe Building Instructions: 1. Cut the straws to five (5) different lengths. 2. Lay a piece of tape on the desk with the sticky side up. 3. Place the straws on the tape in order from longest to shortest. There should be about 1 inch of space between every two straws. 4. The top openings of the straws should be level with each other, as shown in the picture. 5. Fold the rest of the tape over the line of straws to hold them in place. 4-3

13 How does size affect pitch? DESIGN A MUSICAL INSTRUMENT PART 5 TODAY S EXPLORATION QUESTION: What makes different sounds have different notes? In the space below, write AND draw your answer to this question. If you don t know, take a guess. I think that different notes happen when the things that are making the sounds are different sizes. For example, a drum with a big surface makes a low-pitched note, but a drum with a small surface makes a high-pitched note. Similarly, a thick guitar string makes a low-pitched note, but a thin guitar string makes a high-pitched note. I think that smaller objects must vibrate differently than bigger objects. 5-1

14 How does size affect pitch? TODAY S CHALLENGE: Build a two-string guitar using a study base and two rubber-bands one thick and one thin. Make observations of your guitar so that you can tell the difference between high-pitched sounds and low-pitched sounds. What materials did you use to make your guitar? Draw a diagram of your rubber band guitar 5-2

15 Guitar Playing Explorations. Compare the sounds of the thin and thick rubber bands. CIRCLE the answer to each question. (1) One at a time, pluck both rubber bands at their LONGEST length. Which band sounds higher pitched? Thin and long band Thick and long band (2) One at a time, pluck both rubber bands at their SHORTEST length. Which band sounds higher pitched? Thin and short band Thick and short band (3) Now pluck the THIN rubber band at its LONGEST length, but pluck the THICK rubber band at its SHORTEST length. Which band sounds higher pitched? Thin and long band Answers will vary. Thick and short band 5-3

16 How does size affect pitch? GUITAR RECAP: Think about the sounds your rubber-band guitar made. CIRCLE the answer to the question. (1) When did the rubber-bands have the highest pitch? Short Length Medium Length Long Length (2) When they were the same length, which rubber-band had a higher pitch? Thick Rubber-Band Thin Rubber-Band (3) When they were the same length, which rubber band vibrated the fastest? Thick Rubber-Band Thin Rubber-Band CIRCLE the answer that fills in the blank. (4) The longer the rubber-band, the the pitch. Higher Lower (5) The thicker the rubber-band, the the pitch. Higher Lower (6) The longer the rubber-band, the it vibrates. Faster Slower (7) The thicker the rubber-band the it vibrates. Faster Slower 5-4

17 How does size affect pitch? Pan Pipe Activity Drawing a Diagram of Pan Pipes: 1. Draw a quick sketch of your pan pipes in the box to the right. 2. Label the straw with the highest pitch and the straw with the lowest pitch. 3. Add pictures or words to explain which part of the pan pipe is making the sound vibrations. PAN PIPE RECAP: Think about the sounds your pan pipes made. CIRCLE the answer to the question. (1) Which pipe sounded the highest? Shortest Pipe Medium Pipe Longest Pipe (2) Which pipe had the lowest pitch? Shortest Pipe Medium Pipe Longest Pipe In your own words, write a sentence that tells how size and pitch are related. Objects that are smaller in size make sounds that are higher in pitch. 5-5

18 How does tension affect pitch? DESIGN A MUSICAL INSTRUMENT PART 6 TODAY S EXPLORATION QUESTION: Which would make a higher-pitched sound, a loose rubber band or a tight rubber band? Why do you think so? In the space below, write AND draw your answer to this question. If you don t know, take a guess. I think a tight rubber band would make a higher-pitched sound because it will snap back faster when you pluck it. Things that move back and forth (vibrate) fast make higher sounds than things that move back and forth slowly. 6-1

19 How does tension affect pitch? TODAY S CHALLENGE: Use building materials like eye-ring screws, pens, or bolts to connect to your guitar to make tuning pegs that can tighten and loosen its rubber band. Make observations of your guitar so that you can tell how tension changes the pitch of a sound.. RECAP: Think about the sounds your motorized rubber-band guitars made. Answer the questions below. CIRCLE the answer to the question. (1) When did the rubber-band have a higher pitch? Loose Rubber-Band Tight Rubber-Band (2) When did the rubber-band have a lower pitch? Loose Rubber-Band Tight Rubber-Band (3) When did the rubber band vibrate the fastest? Loose Rubber-Band Tight Rubber-Band CIRCLE the answer that fills in the blank. (4) The looser the rubber-band, the the pitch. Higher Lower (5) The looser the rubber-band, the it vibrates. Faster Slower 6-2

20 What happens to sound before it reaches our ears? DESIGN A MUSICAL INSTRUMENT PART 7 TODAY S EXPLORATION QUESTIONS: (1) Imagine you are at a trumpet concert. What happens to the sound between the trumpet and the audience? (How does the trumpet sound get to the audience?) Draw your idea below. Explain your idea below. The sound leaves the trumpet in all directions. The trumpet vibrates the air around it. The vibrations travel throughout the room, including through the air near the ears of the audience members. (2) Now imagine there is a curtain between the trumpet and the audience. Now what happens to the sound between the trumpet and the audience? (How does the trumpet sound get to the audience?) Draw your idea below. Explain your idea below. The trumpet vibrates the air around it again. When the vibrations reach the curtain they still vibrate through the air, but some of their energy is absorbed by the curtain, and the sound loses some volume. 7-1

21 What happens to sound before it reaches our ears? TODAY S CHALLENGE: Your challenge is to build a rattle or maraca using your sturdy box. Make observations of your maraca with and without a muffler. STEP 1. Pick small pieces for noisemakers inside your maraca. STEP 2. Find your sturdy box from Lesson 2. This box will hold the noisemaker pieces. STEP 3. Put the noisemaker pieces inside the sturdy box. STEP 4. Build a cover for the sturdy box. STEP 5. Perform a sound absorption test on the maraca by playing it normally, and with a muffling cover. Record the results in the tables below. Use a microphone or soundtesting device to track noise level. Noise Level from Maraca By Itself(dBA) Test 1 Test 2 Test 3 Higher levels Noise Level from Muffled Maraca(dBA) Test 1 Test 2 Test 3 Lower levels 7-2

22 What happens to sound before it reaches our ears? STEP 6. Fill in the sound pathway below. Absorbed Reflected Transmitted 7-3