But it is too low a frequency for us to hear. (Grades
), So when sound travels through a solid, it travels the same way as it does through air: in a sound wave. In turn, the diaphragm presses the grai… (Answers will vary. Sound - Sound - Open tubes: In an open tube, the standing wave of the lowest possible frequency for that particular length of tube (in other words, the fundamental) has antinodes at each end and a node in the centre. Give them a longer length of string with which to test, and have them decrease the length of string by half each time to see if distance affects the sound. Share your ideas with us! Assume the sound waves travel to the listener without being disturbed. The contents of this digital library curriculum were developed under a grant from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and National Science Foundation GK-12 grant no 0338326. B) velocity. This version is even more kid-friendly because it uses Styrofoam cups. Have students analyze their string telephones using the following questions: How well did the string telephone work? Prediction: Before Part 2 of the activity, have students predict whether they think the string telephone will work better with a loose or taut string. See if you can design new experiments to test any hypotheses that emerge. All you need is some string, a sharpened pencil and a few paper cups to get started. The strings on a guitar have different thickness but may be made of similar material. However, modern telephones rely on the conversion of the sound waves into an electrical signal. Chapter 14, Sound CHAPTER 14 1. So, for this string, there's gonna be nodes at each end. Students should be familiar with sound being described as a wave. communications engineering: The branch of engineering having to do with developing and maintaining technology used for communication, such as telephones. MCQ Questions for Class 9 Science Chapter 12 Sound with Answers MCQs from Class 9 Science Chapter 12 – Sound are provided here to help students prepare for their upcoming Science exam. Physics SOUND Questions 1. If she is holding on to the center of the string with her hand, will the sound still carry through? Recognize that technology has helped people communicate over long distances. Old landline phones were created using the same principle as a string telephone. a project of D2L (www.achievementstandards.org). At what speed does the wave travel along the “E” string? What would they do to further improve their designs? Sound waves move in somewhat the same way through the air, although they are Invisible to us. We now know from experience that these sound waves sound louder when we hear them through solids. Partial Design Process These resources engage students in some of the steps in the engineering design process,
Enjoy learning how sound is carried by playing this fun quiz for Year 3, Year 4, Year 5 and Year 6 students. Therefore, the bottom of the second cup should start to vibrate back and forth just like the bottom of the first cup is vibrating, producing sound waves. In this activity, your voice vibrates the air inside the cup, which are then transferred to the bottom of the cup. Note: This happens because the cup vibrated enough to create a sound wave in the air, which we could then hear. Communication technology is the transfer of messages among people and/or machines over distances through the use of technology. (e) Determine the maximum transverse speed of the string. ... A standing wave is set up in a string of variable length and tension by a vibrator of variable frequency. ), So why was there sound from the cup? Sound waves in air (and any fluid medium) are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves. D) amplitude. Everyone put your ear to you desk and scratch the surface with your fingernail. All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN),
What does sound travel through? Last updated Oct 26 2016. Sound: Lesson 2, String Telephones Activity – Worksheet String Telephones Worksheet Part 1: Questions 1. The waves bounce around in the cup and the second child is able to hear what the first said without being super close. And we'll see, when you set up a standing wave, it's possible that there's nodes in the middle as well but there don't have to be. Enjoy learning how sound is carried by playing this fun quiz for Year 3, Year 4, Year 5 and Year 6 students. Students are introduced to communications engineers as people who enable long-range communication. You'll have learned about waves in your science lessons. When the whole string vibrates as one, it is at its fundamental frequency. What do you hear? Where do the sound waves travel in the string telephone? ), Where do the sound waves travel in the string telephone? How well did the string telephone work? The vibrations are transferred to the string, across the string and into the bottom of the other cup. How does the telephone work? B) A wave carries energy from one place to another. A node exists at the point or points where, in a pipe containing a standing wave, the pressure is equal to the ambient pressure outside the pipe. ), Where do you think the vibration went? A) A wave can have both transverse and longitudinal components. The sound can travel in air when: (a) Particles of medium travel from one […] Any reusable equipment that is necessary to teach the activity is not included in this estimate; see the Materials List/Supplies for details. Maybe this is due to my great love and appreciation of music. The diaphragm presses against these carbon grains. (The answer is yes, tiny parts of the desk are moving with the sound wave. Hi! 3. 3 -
Question/Answer: Ask students the questions found in the Procedures section. Make a tin-can telephone to further investigate how sound can travel along a string (tip: these work best when the string is taut). An electric current carries the sound to the telephone of the person he is talking to. Step 6 of Part 1: Hold the string taut, as it comes directly out of the cup bottom.copyrightCopyright © 2008 Michael Bendewald, ITL Program, University of Colorado at Boulder. Where do the sound waves travel in the string telephone? A string telephone works very much like a landline phone. Ask students the following questions, and discuss as a class. (Answers will vary. Draw a picture in the space below and show arrows for where the sound waves went. Frequency is related to the pitch of a sound, or how high or low the sound is. Take one minute to discuss with the people around you what is happening. Or did it just disappear? are like this. Experiment with your string telephone by gently pulling the string taut and then letting it fall loose. Sound waves travel at 343 m/s through the air and faster through liquids and solids . The high-pressure regions are called compressions and the low-pressure regions are called rarefactions. Sound travels through the air but it travels even better through solids such as your cup and string, allowing you to hear sounds that … Ask the students the following questions and discuss as a class: A. The fundamental frequency (f1) is thuswhere Lo is the length of the open tube. Pull string through the cup and tie a knot (see Figure 2). sound is able to travel along a string by something thats called sound waves! String types that do not dampen the vibrations will also enhance the function of the string telephone. Use a nail to make a small hole in the bottom of a paper cup (see Figure 1). A telephone has two main parts: (1) the transmitter and (2) the receiver. How much time does it take for a wave on the string to travel from the center of the circle to the ball? Have students compare the loudness of sound with the distance of the cups. (Answer: The motionless fingers holding the string feel vibrations.). For this string though, we're making sure that there have to be nodes at each end. You can hear surprisingly far using a string telephone if help the right way! Effectively, if you consider the standing wave to be the superposition of two traveling waves (one to the left and one to the right) then the motion of the support on the sound board results in imperfect reflection of the sound wave. I believe that the sound travels at exactly the same speed in both provided they are both made of the same material. (Grades 3 - 5). After making your string telephone, read the string telephone explanation with your kids to discover why it works! While some of these resources may focus heavily on the brainstorm and design steps,
), What could you do to make the string telephone work better? Students learn how engineers build shake tables that simulate the ground motions of the Earth caused by seismic waves in order to test the seismic performance of buildings. These waves travel in the form of sound. Although no charge or fee is required for using TeachEngineering curricular materials in your classroom, the lessons and activities often require material supplies. Conclusion Yes, the waves will travel through both strings uninterrupted. The cup transferred the vibration into the air, which we could then hear.). But if you want to make a call to another country, a few more things are involved. Extensions. If the string is loose, the sound is less. These compressions and rarefactions travel through the air in the form of longitudinal waves, which have the same frequency as the sound source. In a demonstration, students discuss the tendency of sound to diminish with distance and model this phenomenon using a slinky. Soft materials tend to absorb more sound that solid ones; when more sound is being absorbed, your friend on the other end of the line cannot hear as well. https://www.teachengineering.org/activities/view/cub_sound_lesson02_activity1 Hold string straight out from cup with two fingers of one hand, pressing your fingernail to hold it extra tight (see Figure 3). It did not just disappear. Md. To take a more realistic example with a more realistic speed of sound on a string, consider the lowest pitched string on a violin. Do you agree with this alignment? Assume the sound waves travel to the listener without being disturbed. Question #124146. Speed of a sound wave can also be affected by the density, temperature, and elasticity of the medium through which the sound waves travel. What do you feel? In the case of tin … Review their answers to gauge their mastery of the subject. The second person can hear the sound waves and can therefore hear what the first person says. Then, they combine the string and cup with a partner to model a string telephone. When you talk into the cup your voice sends sound waves inside the cup, vibrating the bottom of the cup. 2. If the string is kept tight, the sound waves will travel. (Answer: It is in the cup, and it is louder.) The length of the “E” string on a guitar is 65 cm and it produces a sound with a frequency of 82.4 Hz. The points in a standing wave that appear to remain flat and do not move are called nodes. They must travel through a medium, and it is the medium that vibrates as the waves travel through. Explore the wonderful world of waves! Try experimenting with different lengths of string, types of string, and types of cups to see which produces the best sound over the longest distance. That wave would travel through the air at the speed of sound in the air, which is about 350 m/s, and it would have a very long wavelength in the air of about 350/.5= 700m. Some activities or lessons, however, were developed to stand alone, and hence, they might not conform to this strict hierarchy. Tests are often designed to identify failure points or difficulties, which suggest the elements of the design that need to be improved. It is a particular case of mechanical telephony, where sound is converted into vibrations along liquid or solid medium. Have students answer the worksheet questions. The sound wave actually moves the tiny particles, or molecules, that make up the solid. We are going to model a simple string guitar, analyze how sound moves through our model, and think about how the model relates to a telephone. (a) in what direction does this wave travel? The angular speed of the ball is v 5 12.0 rad/s. Sound is basically the movement of the air vibrating from the sound produced by something making a noise. E) A transverse wave is one in which the disturbance is parallel to the direction of travel. A sound wave coming from a tuba has a wavelength of 1.50 m and travels to your ears at a Explain to students that engineers have helped sound travel great distances by designing devices that convert the sound waves into electricity and back. A tin can telephone is a type of acoustic speech-transmitting device made up of two tin cans, paper cups or similarly shaped items attached to either end of a taut string or wire. Discuss how the sound has changed, and what this shows about the way sound travels. How does sound travel through telephone lines - trivia question /questions answer / answers. 2. Would they change the materials for the cups or string? Did you know that sound is a wave? 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