Answer: 9.7 days
Explanation:
Applying Kepler's 3rd law, we can write the following proportion:
(Tm)² / (dem)³ = (Tsat)² / (dem/2)³
(As the satellite is placed in an orbit halfway between Erth's center and the moon's orbit).
Simplifyng common terms, and solving for Tsat, we have:
Tsat = √((27.3)²/8) = 9.7 days
The answer is d.... Knife.
Hope this helped :)
To solve this problem we will apply the concepts related to the Doppler effect. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other. Mathematically it can be described as

Here,
=frequency received by detector
=frequency of wave emitted by source
=velocity of detector
=velocity of source
v=velocity of sound wave
Replacing we have that,


Therefore the frequencty that will hear the passengers is 422Hz