Question

In afternoon, the decibel level of a busy freeway is 100 dB with 100 cars passing a given point every minute. Late at night, the traffic flow is only 20 cars per minute. What is the late-night decibel level? A. 20 dB b. 50 dB c. 80 dB d. 88 dB e. 93 dB

Answer 1

option E

Step-by-step explanation:

given,

decibel level of a busy freeway = 100 dB

when flow is = 100 car/minutes

traffic flow= 20 car/minute

Intensity factor =
`(I)/(I_0)`

=
`(20)/(100)`

=
`(1)/(5)`

`\Delta \beta = 10 log(I)/(I_0)`

`\Delta \beta = 10 log(1)/(5)`

`\Delta \beta = - 6.989\ dB`

The late night decibel level

= 100 - 6.989

= 93

The correct answer option E