In the afternoon,the decibel level of a busy freeway is 80 dB with 100 cars passing a given point every minute.Late at night,the traffic flow is only 5 cars per minute.What is the late-night decibel level?
A)77 dB
B)74 dB
C)70 dB
D)68 dB

Question

Quizplus · Accepted Answer

The decibel level is affected by the number of cars passing by as well as the time of day. Late at night, when there are only 5 cars passing per minute, the decibel level will be lower than during the afternoon rush hour.

To calculate the late-night decibel level, we can use the following equation:

L2 = L1 - 10 log (N2/N1)

Where L1 is the original decibel level (80 dB), N1 is the original number of cars (100 per minute), N2 is the new number of cars (5 per minute), and L2 is the new decibel level we are trying to find.

Plugging in the values, we get:

L2 = 80 - 10 log (5/100) 
L2 = 68 dB

Therefore, the best choice is D, 68 dB.

In the Afternoon,the Decibel Level of a Busy Freeway Is