Sound intensity is inversely proportional to the square of the distance between the source and the receiver.
That is
I = k/r^2
where
k = constant
r = radius
When r=1, the intensity is I₁ = k/1 = k
When r=3, the intensity I₂ = k/3² = k/9
Therefore
I₂ = I₁ /9
In decibels,
I = 10 log₁₀(I/I₀)
where I₀ = reference intensity
When r=1,
10 log₁₀ (I₁/I₀) = 270
When r =3,
10 log₁₀ (I₂/I₀) = 10 log₁₀ [(I₂/I₁)*(I₁/I₀)]
= 10 log₁₀ [(1/9)*(I₁/I₀)]
= 10 log₁₀(1/9) + 270
= 260.5
Answer: 260.5 dB (nearest tenth)
Answer:
1. Electromagnetic spectrum
2. Electromagnetic radiation
3. Radiant energy
4. Infared waves
5. Electricmagnetic radiation or Infared waves
6. Radio waves
7. Gamma rays
8. Radio waves
9. Ultraviolet rays
10. This is because it doesn’t contain water or a substance.
11. You should use sunscree and a hat to protect your skin from UV light that might cause skin cancer.
Hope this helps
Halogens are highly reactive nonmetal elements in group 17 of the periodic table. ... Halogens are among the most reactive of all elements. They have seven valence electrons, so they are very “eager” to gain one electron to have a full outer energy level.
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