Physics PLEASE HELP
posted by Anonymous .
An interstate highway has been built though a poor neighborhood in a city. In the afternoon, the sound level in a rented room is 114.0 dB as 172 cars pass outside the window every minute. Late at night, the traffic flow is only 7 cars per minute.
(b) What is the sound intensity at night? (c) What is the average latenight sound level?

86 cars (half of them) is 3 db down
43 cars will be down another 3 db
22 cars (appx) will be down another 3 db
11 cars will be down another 3 db
I estimating, 7 cars will be 11414 db.
Doing the math:
Intnsity=10log(power/E12)
112=10log(EachCar*172/E12)
11.2=log( )
taking theantilog of each side.
E11.2=Each car*172/E12
E.8=each car*172
each car= .158/172
sound intensity at night:
Inight=10log(7*.158/172E12)=98db