Two In-Phase Loudspeakers Are Some Distance Apart

question 32

Multiple Choice

Two in-phase loudspeakers are some distance apart. They emit sound with a frequency of 1536 Hz. You move between the speakers, along the line joining them, at a constant speed of 2.8 m/s. What beat frequency do you observe? The speed of sound in the room is 330 m/s.

• A) 13 Hz
• B) 431 Hz
• C) 26 Hz
• D) 4.7 Hz
• E) 118 Hz

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Definitions:

Money Supply Growth Rate

The speed at which the quantity of money circulating within an economy is growing.

Unemployment Rate

The proportion of the overall workforce that is not employed but is actively looking for a job and ready to work.

Natural Rate of Unemployment

The long-term rate of unemployment around which the labor market is in balance, reflecting the number of people who are naturally jobless due to factors such as frictional and structural unemployment.

Money Supply Growth Rate

The rate at which the amount of money available in an economy increases over a specific period.