A boat travels at 30 mph for a huge, solid cliff that is about 3,000 meters away. When the horn on the boat makes a toot, you can hear the initial sound directly from the horn and also an echo from the cliff wall some time later. How does the frequency of the echo compare with the frequency of the horn before the ship moved?
Group of answer choices

The frequency of the echo is slightly increased.

The frequency of the echo is slightly decreased.

The frequency is unchanged.

Not enough information to determine.

The frequency of the echo is slightly decreased

Explanation:

Given

speed of boat

cliff is away

when boat is still , suppose t is the time taken by the echo to reach observer on the boat

But as soon as boat starts moving  the distance between cliff and boat decreasing and time for echo to reach observer also decreases

and we know

therefore frequency of the echo slightly decreased.

it is the second option.

the answer would most likely be c, because if it's a comical piece of information, it may likely not be true, if it's a site that allows anybody to edit the content, it could mean a five year old is typing the info, and if it's a tv show produced by a celeb, it may have a biased opinion.