Two In-Phase Loudspeakers That Emit Sound with the Same Frequency

question 40

Multiple Choice

Two in-phase loudspeakers that emit sound with the same frequency are placed along a wall and are separated by a distance of 5.00 m.A person is standing 12.0 m away from the wall,equidistant from the loudspeakers.When the person moves 1.00 m parallel to the wall,she experiences destructive interference for the first time.What is the frequency of the sound? The speed of sound in air is 343 m/s.

• A) 211 Hz
• B) 256 Hz
• C) 422 Hz
• D) 512 Hz
• E) 674 Hz

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Definitions:

Thoracic Duct

The largest lymphatic vessel in the body, which drains lymph from the lower half of the body and the left upper part into the bloodstream.

Lymphatic Duct

A large vessel in the lymphatic system that drains lymph from the lymphatic vessels into the venous system.

Vena Cavae

The two major veins (superior vena cava and inferior vena cava) that carry deoxygenated blood from the body back to the heart.

Cisterna Chyli

A dilated sac at the lower end of the thoracic duct into which lymph from the intestinal trunk and two lumbar lymphatic trunks flows.