Answer:
73 db
Explanation:
A single air conditioner is equivalent to 70 dB frequency. An extra air conditioning unit would therefore double the sound frequency. It does not, however, double the decibels to 140 dB. Instead, it adds only 3 dB to the 70 dB, making the total decibels of two air conditioning units equal to 73 db
Hence the correct option is b that is 73 db
Answer:
Decreases by
times
Explanation:
The intensity of a sound is defined as the energy of the sound that is flowing in an unit time through the unit area which is in the direction that is perpendicular to the direction of the sound waves movement.
The intensity of energy is described by the inverse square law. It states that the intensity varies inversely with the distance square of the distance.
In other words, the sound intensity decreases as inversely proportional to the squared of the distance. i.e. ![$\frac{1}{r^2}$](https://tex.z-dn.net/?f=%24%5Cfrac%7B1%7D%7Br%5E2%7D%24)
In the context when the distance was 3 m, the intensity of the sound was = ![$\frac{1}{9}$](https://tex.z-dn.net/?f=%24%5Cfrac%7B1%7D%7B9%7D%24)
But when the distance became 6 cm or 0.06 m, the sound intensity decreases by = ![$\frac{1}{0.06^2}$](https://tex.z-dn.net/?f=%24%5Cfrac%7B1%7D%7B0.06%5E2%7D%24)
=
times
Nickel has a happy amount of 28 electrons.
You didn't mention it, but the trumpeter herself has to be standing still.
<span>Person C, the one running towards the trumpeter, hears a pitch
that is higher than B-flat. (A)
Person B, the one running away from the trumpeter, hears a pitch
that is lower than B-flat.
Person D, the one standing still the whole time, hears the B-flat.</span>
Hi There,
This is False.
Hope this helped!