Question

A construction explosion has an intensity I of 1.25 x 10–4 W/m2. Find the loudness of the sound in decibels if W/m2. Round to the nearest tenth.

A. 81 decibels
B. 161 decibels
C. 82.2 decibels
D. 12.5 decibels

Answer 1

Explanation:

1. B) logb(q^2t^8)

2. D) None of these (it is actually log (x^4/(x+2)^6) :D)

3. B) log5(7)+5log5(a)

4. C) 6.209

5. A) 81 decibels

Answer 2

We solve this problem by using the decibels formula which is expressed as:

dB = 10 x log (Isig/Iref)

where dB is decibels, Isig is the intensity of the signal and Iref is the intentsity of the softest sound the human ear can hear which has a value of 10^-12.

We solve as follows:
dB = 10 x log (1.25 x 10–4 / 10^-12 ) = 80.97 decibels

Therefore, the correct answer is option A, 81 decibels.