When You Hear the Horn of a Car That Is

question 35

Multiple Choice

When you hear the horn of a car that is approaching you, the frequency that you hear is larger than that heard by a person in the car because for the sound you hear

• A) wave crests are farther apart by the distance the car travels in one period.
• B) wave crests are closer together by the distance the car travels in one period.
• C) the car gets ahead of each wave crest before it emits the next one.
• D) the speed of sound in air is increased by the speed of the car.
• E) a speeding car emits more wavecrests in each period.

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Definitions:

Alternating Current

The form in which electrical current is generated at power stations and transmitted along power lines to customers. Alternating current is created by causing electrons to flow in an alternating positive and negative manner.

AC Generator

A machine that converts mechanical energy into alternating current electrical energy.

DC Motor

An electric motor that runs on direct current electricity, widely used in various applications due to its simplicity and ease of control.

Magnetic Fields

Invisible fields produced by electrically charged objects, affecting the behavior of charged objects in the vicinity.