The loudness, L of a sound in decibels (dB) can be calculated using the formula L = 10 log ( IIo), where I is the intensity

of the sounds in watts per square metre (W/m2) and Io = 10-12 W/m2

a. A teacher is speaking to a class. Determine the intensity of the teacher's voice if the sound level is 50 dB.

b. Determine the intensity of the music in the earpiece of an MP3 player if the sound level is 84 dB.

c. Determine how many times more intense is the sound of the music than the teacher's voice.