The distance between Earth and the Moon was determined by measuring the time it took for light waves from Earth to travel to the Moon and back. Why was it not possible to use sound waves for this experiment?
A)Sound waves must move through a substance.
B)Sound waves would change frequency on the return to Earth.
C)Sound waves move too slowly for the technique to be accurate.
D)Sound waves move more slowly in Earth's atmosphere than in space.

Question

Quizplus · Accepted Answer

Sound waves require a medium (such as air, water, or solid materials) to travel through, but space is a vacuum, lacking such a medium for sound waves to propagate.

The Distance Between Earth and the Moon Was Determined by Measuring