Question

A sound-producing object is moving toward an observer. The sound the observer hears will have a frequency ______ that actually being produced by the object.
lower than
the same as
Higher than

Answer 1

Answer:

Higher than

Explanation:

By Doppler's effect, when there is relative motion between source and observer, the observer does not hear the actual frequency of the sound. The apparent frequency heard by the observer is either more or less than the source depending on whether the observer and source are moving closer or away respectively.

When the sound source moves towards the observer, the later would hear a frequency which is higher than the actual source frequency.

Answer 2

A sound-producing object is moving toward an observer. The sound the observer hears will have a frequency  higher than that actually being produced by the object.