# The piano string tuned to middle C vibrates with a frequency of by fionan

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```									Unit 13 Lesson 3 Worksheet Bank – Properties of Sound Waves 1. The piano string tuned to middle C vibrates with a frequency of 264 Hz. Assuming the speed of sound in air is 343 m/s, find the wavelength of the sound waves produced by the string. [1.30 m] 2. A piano emits frequencies that range from a low of about 28 Hz to a high of about 4200 Hz. Find the range of wavelengths in air attained by this instrument when the speed of sound in air is 340 m/s. [0.081 m – 12.14 m] 3. A tuning fork produces a sound with a frequency of 256 Hz and a wavelength in air of 1.35 m. a. What value does this give for the speed of sound in air? [345.6 m/s] b. What would be the wavelength of the wave produced by this tuning fork in water in which sound travels at 1500 m/s? [5.86 m] 4. If you hear a higher pitch from a trumpet than from a saxophone, how do the frequencies of the sound waves from the trumpet compare with those from the saxophone? 5. Dolphins can produce sound waves with frequencies ranging from 0.25 kHz – 220 kHz, but only those at the upper end of the spectrum are used in echolocation. Explain why high-frequency waves work better than lowfrequency waves. 6. Sound pulses emitted by a dolphin travel through 20o C ocean water at a rate of 1450 m/s. In 20oC air, these pulses would travel 342.9 m/s. how can you account for this difference in speed? 7. Opera singers have been known to set crystal goblets in vibration with their powerful voices. In fact, an amplified human voice can shatter the glass, but only at certain fundamental frequencies. Speculate about why only certain fundamental frequencies will break the glass. 8. Electric guitars, which use electric amplifiers to magnify their sound, can have a variety of shapes, but acoustic guitars must have an hourglass shape. Explain why. 9. What are the first three harmonics in a 2.45 m long pipe that is open at both ends? [70.41 Hz, 140.82 Hz, 211.22 Hz] What are the first three harmonics of this pipe when one end of the pipe is closed? [35.20 Hz, 105.61 Hz, 176.02 Hz] Assume that the speed of sound in air is 345 m/s for both of these situations.

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Unit 13 Lesson 3 Worksheet Bank – Properties of Sound Waves 10. A violin string that is 50 cm long has a fundamental frequency of 440 Hz. What is the speed of the waves on this string? [440 m/s] 11. What is the fundamental frequency of a 0.20 m long organ pipe that is closed at one end, when the speed of sound in the pipe is 352 m/s? [440 Hz] 12. On a piano, the note middle C has a fundamental frequency of 264 Hz. What is the second harmonic of this note? [528 Hz] If the piano wire is 66 cm long, what is the speed of waves on the wire? [348.5 m/s] 13. A piano tuner using a 392 Hz tuning fork to tune the wire for G-natural hears four beats per second. What are the two possible frequencies of vibration of this piano wire? [388 Hz & 396 Hz] 14. Sound waves are ____________ waves. a. longitudinal b. transverse c. compression d. a & b e. a & c 15. When a sound wave is graphed as a sine wave, the compressions correspond to the _______ on the sine graph and the rarefactions correspond to the _________. 16. Compressions are regions of ______ density, _______ pressure and the molecules are ___________. (use high, low, spread apart, or close together) 17. Rarefactions are regions of ______ density, _______ pressure and the molecules are ___________. (use high, low, spread apart, or close together) 18. The frequency of a sound wave can be defined as… 19. The range frequencies a human can hear is ______________. 20. Sound waves lower than 20 Hz are called ___________. List some examples of when this type of wave is used. 21. Sound waves higher than 20,000 Hz are called _________. List some examples of when this type of wave is used.

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Unit 13 Lesson 3 Worksheet Bank – Properties of Sound Waves 22. The higher the frequency, the ____________ the wavelength. 23. How are pitch and frequency related? Which one is subjective (perceived differently by individuals)? Which one is objective (can be measured precisely)? 24. List in order of increasing speed of sound the 3 states of matter. Why does sound travel fastest through the medium that it does? 25. How does the temperature of a gas medium affect the speed of sound? 26. Draw a representation of a spherical sound wave. Label the wave front, wavelength, source, and ray. Draw the sine curve that corresponds to your diagram. 27. If the intensity of a person’s voice is 5.2 x 10-7 W/m2 at a distance of 1.2 m, how much sound power does that person generate? 28. The softest sound human can hear is known as the ______________, while the loudest sound a human can tolerate is known as the __________. 29. What is an example of forced vibration? 30. What is natural frequency? 31. Explain resonance. Give at least one example. 32. Why is our outer ear shaped the way it is? 33. What types of waves are produced on strings and in air columns of instruments? 34. The ____________ frequency is the lowest possible frequency of a standing wave. 35. In what situation can you hear ALL of the harmonics? In what situation can you only hear the ODD harmonics? 36. Explain what is happening when you can hear beats. 37. If the speed of sound is 344 m/s, what are the first three harmonics in a 0.75 m long pipe with both ends open?

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Unit 13 Lesson 3 Worksheet Bank – Properties of Sound Waves 38. If the speed of sound is 340 m/s, what are the first three harmonics in a 1.5 m long pipe with one end closed? 39. On a piano, the note E has a fundamental frequency of 320 Hz. What is the second harmonic of this note? If the piano wire is 60 cm long, what is the speed of waves on the wire? 40. You have two tuning forks, one with a frequency of 345 Hz and a second with an unknown frequency. If you can hear 6 beats per second, what frequency could the unknown tuning fork be?

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