Log functions:

A new car has an interior sound level of 70 dB at 50 km h. A second car, at the
same speed, has an interior sound level that is two times more intense than that
of the new car. Calculate the sound level inside the second car.

1 answer

NEW CAR:

10LogN = 70db,
Divide boh sides by 10:
LogN = 7,
N = 10^7.

2ND CAR:

N = 2*10^7,
10Log(2*10^7) = 10*(0.3010+7) = 73db.