If a source of sound waves is rapidly approaching a person, the sound heard by the person appears to have

Answer choices are:

a. a period higher than the original period.

b. a pitch lower than the original pitch.

c. an amplitude lower than the original amplitude.

d. a frequency higher than the original frequency.

Correct answer choice is:

D. A frequency higher than the original frequency.

Explanation:

This is a true case of Doppler's effect. The Doppler effect can be defined as the effect originated by a traveling source of waves in which there is a visible higher variation in pulse for observers towards what the source is progressing and a visible descending shift in rate for observers from what the source is dropping.

lysosome is this part of the cell is surrounded by a very thick outer membrane to protect the rest of the cell from its strong enzymes.

the electromagnetic energy from the sun arrives in the form of visible and invisible light.