The intensity of the sound in decibels is .

The intensity of the reference level is .

The loud speaker is placed in distance of .

The sound is spreading in uniform spherical.

The intensity of sound is , where is output power and is area.

Find the intensity of sound. \ \

The intensity of sound in decibels is .

\ \

.

Step 2:

The area of the uniform spherical is .

.

Substitute and in .

.

The output power is .

Solution:

The output power is .

Part(B):

The intensity of the sound in decibels is .

From part (A): The output power is .

Find the intensity of the sound. \ \

The intensity of sound in decibels is .

\ \

.

The sound is spreading in uniform spherical.

Find the distance between loud speaker and decibel register.

The intensity of sound is , where is output power and is area.

The area of the uniform spherical is .

.

The distance between loud speaker and decibel register is .