Mastering Physics Solutions: The Decibel Scale

Mastering Physics Solutions: The Decibel Scale

On May 24, 2013, in Chapter 14: Sound, by Mastering Physics Solutions

Part A = 10 dB
Part B = 20 dB
Part C = 3,6,9 dB

What is the sound intensity level Β, in decibels, of a sound wave whose intensity is 10 times the reference intensity (i.e., I = 10I0)?
What is the sound intensity level Β, in decibels, of a sound wave whose intensity is 100 times the reference intensity (i.e., I = 100I0)?
Calculate the change in decibels (ΔΒ2, ΔΒ4, and ΔΒ8) corresponding to f = 2, f = 4, and f = 8.

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Mastering Physics Solutions: Fundamental Wavelength and Frequency Ranking Task

Mastering Physics Solutions: Fundamental Wavelength and Frequency Ranking Task

On February 20, 2013, in Chapter 14: Sound, by Mastering Physics Solutions

Part A = (B,F) < (A,C,E) < D (increasing order)
Part B = (C,D,F) < (A, B) < E (increasing order)

A combination work of art/musical instrument is illustrated. Six lengths of identical piano wire are hung from the same support, and masses are hung from the free end of each wire. Each wire is 1, 2, or 3 units long, and each supports 1, 2, or 4 units of mass. The mass of each wire is negligible compared to the total mass hanging from it. When a strong breeze blows, the wires vibrate and create an eerie sound.

Rank each wire-mass system on the basis of its fundamental wavelength.
Rank each wire-mass system on the basis of its wave speed.

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Mastering Physics Solutions: Question 14.4

Mastering Physics Solutions: Question 14.4

On December 20, 2011, in Chapter 14: Sound, by Mastering Physics Solutions

Part A = all of the preceding

The speed of sound in air A. is about 1/3 km/s. B. is about 1/5 mi/s. C. depends on temperature. D. all of the preceding.

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Mastering Physics Solutions: Exercise 14.64

Mastering Physics Solutions: Exercise 14.64

On December 20, 2011, in Chapter 14: Sound, by Mastering Physics Solutions

Part A = f = 511Hz Click to use the calculator/solver for this part of the problem

A closed organ pipe has a fundamental frequency of 528 Hz (a C note) at 20° C. What is the fundamental frequency of the pipe when the temperature is 2° C?

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Mastering Physics Solutions: Exercise 14.52

Mastering Physics Solutions: Exercise 14.52

On December 20, 2011, in Chapter 14: Sound, by Mastering Physics Solutions

Part A = fb = 4.2 Hz Click to use the calculator/solver for this part of the problem

Two identical strings on different cellos are tuned to the 440 Hz A note. The peg holding one of the strings slips, so its tension is decreased by 1.9 %. What is the beat frequency heard when the strings are then played together?

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Mastering Physics Solutions: Exercise 14.51

Mastering Physics Solutions: Exercise 14.51

On December 20, 2011, in Chapter 14: Sound, by Mastering Physics Solutions

Part A = fo = 426 Hz Click to use the calculator/solver for this part of the problem
Part B = fo = 377 Hz Click to use the calculator/solver for this part of the problem

While standing near a railroad crossing, you hear a train horn. The frequency emitted by the horn is 400 Hz. If the train is traveling at 75 km/hr and the air temperature is 25 °C, what is the frequency you hear when the train is approaching you?

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