Answer:
Explanation:
If a perfect vacuum existed in any volume, then no sound would be able to propagate through it, because a sound wave is a pressure wave, and there would be identically zero pressure. Of course, we could get into speculations about “dark energy” or “vacuum energy” supporting pressure waves, but let’s not go there.
Answer:
Part(a): The frequency is
.
Part(b): The speed of the wave is
.
Explanation:
Given:
The distance between the crests of the wave,
.
The time required for the wave to laps against the pier, 
The distance between any two crests of a wave is known as the wavelength of the wave. So the wavelength of the wave is
.
Also, the time required for the wave for each laps is the time period of oscillation and it is given by
.
Part(a):
The relation between the frequency and time period is given by

Substituting the value of
in equation (1), we have

Part(b):
The relation between the velocity of a wave to its frequency is given by

Substituting the value of
and
in equation (2), we have

The answer would be false
The statement is false because as the temperature of water is decreased from 4C to 0C, <em>expansion</em> occurs.
You should understand that this is very weird behavior for any compound ... within a small temperature range, the stuff actually gets bigger as it gets colder. That's why cubes float in your sody, and bergs float in the ocean.
Water is one of only two known substances that do this. And if water didn't do it, then life on Earth would not be possible.
Hmmm....