To solve the problem it is necessary to apply the concepts related to sound intensity. The most common approach to sound intensity measurement is to use the decibel scale:
Where,
is a reference intensity. It is the lowest or threshold intensity of sound a person with normal hearing can perceive at a frequency of 1000 Hz.
I = Sound intensity
Our values are given by,
For each auto the intensity would be,
Therefore the sound intesity for the 7 autos is
The sound level for the 7 cars in dB is
Stars are formed in <u>nebulas</u>, interstellar clouds of dust and gas.
<span>h ( t) = h(1 sec) = -16t^2 + 541
so h (2 sec) = -16*(2)^2 + 541 = -64 + 541 = <span>477 ft
Therefore, </span></span>the height of the rock after 2 seconds is 477 feet.
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Answer:
20m/s
Explanation:
it covers 20 metres in a second
