Two In-Phase Loudspeakers Are Some Distance Apart

question 38

Multiple Choice

Two in-phase loudspeakers are some distance apart. They emit sound with a frequency of 572 Hz. A microphone is moved between the speakers to record the wave amplitude at points along that line. What is the spacing between points where constructive interference occurs? The speed of sound in air is 343 m/s.

• A) 0.300 m
• B) 0.600 m
• C) 0.900 m
• D) 1.20 m
• E) 1.50 m

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Rate Of Interest

The percent of principal charged by the lender for the use of its money.

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The value of an investment at a specific date in the future, calculated by applying a rate of interest or return to the principal amount.

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Occurring once every year or relating to a period of one year.

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The prosperity or setback experienced by an investment over a fixed timeline, posited as a percentage of the investment’s nascent cost.