The Longitudinal Displacement of a Mass Element in a Medium

question 29

Multiple Choice

The longitudinal displacement of a mass element in a medium as a sound wave passes through it is given by s = s_m cos (kx - ωt) .Consider a sound wave of frequency 440 Hz and wavelength 0.75m.If s_m = 12 µm, how long does it take an element of air to move from a displacement of 12 µm to a displacement of 0 µm?

• A)0.57 ms
• B)1.1 ms
• C)2.3 ms
• D)3.4 ms
• E)4.6 ms

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Definitions:

Matching

An accounting principle where expenses are recorded in the period they are incurred to generate revenues.

Ending Inventory

The total value of goods available for sale at the end of an accounting period.

Cost of Goods Sold

The direct costs attributable to the production of the goods sold by a company.

LIFO

A method of inventory valuation called "Last-In, First-Out," where the most recently acquired items are the first to be expensed.