It is a stretch of the atmosphere ranging from the upper mesosphere to the lower parts of the thermosphere. It’s useful to us in radio communication.
<h3><u>Answer;</u></h3>
Period = 1/17 seconds
<h3><u>Explanation;</u></h3>
- Wavelength is related to period by the expression:
<em>speed = wavelength / period
</em>
- If we are given the speed, then we can easily calculate the period at the wavelength of 20 m.
<em>Given the speed of sound wave as 340 m/s </em>
<em>Period = Wavelength/ speed</em>
<em> = 20 m/340 m/s</em>
<em> </em><u><em>= 1/17 seconds</em></u>
Answer:
oxygen was produced by phosynthesis
Explanation:
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Answer:
Amplitude is decreased by a factor of 
if intensity is decreased by a factor of 3.
Explanation:
Intensity of a sound wave is directly proportional to the square of its amplitude.
Therefore, if intensity is 
and amplitude is 
, then
, where, 
is constant of proportionality.
Now, if intensity of sound wave is decreased by a factor of 3. So,
New intensity is, 
Plug in 
for . This gives,
Therefore, amplitude is decreased by a factor of .
