Question

One of the loudest sounds in recent history was that made by the explosion of Krakatoa on August 26-27, 1883. According to barometric measurements, the sound had a decibel level of 180 dB at a distance of 161 km. Assuming the intensity falls off as the inverse of the distance squared, what was the decibel level on Rodriguez Island, 4,800 km away?

Answer 1

Answer:

150.51 dB

Step-by-step explanation:

Data provided in the question:

decibel level of sound at 161 km distance = 180 dB

d₁ = 161 km

d₂ = 4800 km

I₁ = 180 db

The formula for intensity of sound is given as:

I = $10\log(\frac{I_2}{I_1})$

and the relation between intensity and distance is given as:

I ∝ $\frac{1}{d^2}$

or

Id² = constant

thus,

I₁d₁² = I₂d₂²

or

$\frac{I_2}{I_1}=\frac{d_1}{d_2}$

therefore,

I = $10\log(\frac{d_1}{d_2})^2$

or

I = $10\times2\times\log(\frac{161}{4,800})$

or

I = 20 × (-1.474)

or

I = -29.49

Therefore,

the decibel level on Rodriguez Island, 4,800 km away

= 180 - 29.49

= 150.51 dB