Answer:

Answers: See below

The equation which relates the intensity of a sound wave to its decibel level is:

dB = 10 * log( I / 1.0 x 10-12 W/m2)

where I = intensity of the sound in units of W/m2. Using this equation, parts a - d can be computed in straightforward fashion.

a. dB = 10 * log( 1 x 10-5 W/m2 / 1.0 x 10-12 W/m2) = 70. dB

b. dB = 10 * log( 1 x 10-2 W/m2 / 1.0 x 10-12 W/m2) = 100. dB

c. dB = 10 * log( 6.1 x 10-6 W/m2 / 1.0 x 10-12 W/m2) = 68 dB

d. dB = 10 * log( 2.2 x 10-4 W/m2 / 1.0 x 10-12 W/m2) = 83 dB

e. The intensity is 4 x (2.2 x 10-4 W/m2 ) or 8.8 x 10-4 W/m2 ; so the decibel rating is 89 dB.

f. The intensity is 7 x (2.2 x 10-4 W/m2 ) or 1.54 x 10-3 W/m2 ; so the decibel rating is 92 dB.

g. The intensity is 10 x (2.2 x 10-4 W/m2 ) or 2.2 x 10-3 W/m2 ; so the decibel rating is 93 dB.

h. The intensity is 100 x (2.2 x 10-4 W/m2 ) or 2.2 x 10-2 W/m2 ; so the decibel rating is 103 dB.

i. dB = 10 * log( 7.5 x 10-6 W/m2 / 1.0 x 10-12 W/m2) = 69 dB

j. dB = 10 * log( 2.5 x 10-4 W/m2 / 1.0 x 10-12 W/m2) = 84 dB