A Fire Engine Approaches a Wall at 5 M/s While

question 69

Multiple Choice

A fire engine approaches a wall at 5 m/s while the siren emits a tone of 500 Hz frequency. At the time, the speed of sound in air is 340 m/s. How many beats per second do the people on the fire engine hear?

• A) 0
• B) 15
• C) 29
• D) 63
• E) 250

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Definitions:

Pharynx

The muscular tube that connects the mouth and nasal passages with the esophagus and larynx, playing a key role in both the respiratory and digestive systems.

Bolus

A small rounded mass of a substance, especially of chewed food at the moment of swallowing.

Esophagus

The part of the digestive tract that conducts food from the pharynx to the stomach.

Amylase

An enzyme that catalyzes the hydrolysis of starch into sugars, present in saliva and pancreatic fluid.