To solve this problem it is necessary to apply the concepts related to Sound Intensity. The unit most used in the logarithmic scale is the decibel and mathematically this is expressed as
Where,
= Sound intensity level in decibels
I = Acoustic intensity on the linear scale
Hearing threshold
According to the values, the total intensity is 32 times the linear intensity and the value in decibels is 83dB
So:
Therefore the sound intensity due to one person is 67.948dB
C) a substance that flows
Answer:
The acceleration is: 
Explanation:
Recall that acceleration is defined as the change of velocity over the time it took to produce this change. This is expressed mathematically as:
with 
being the initial velocity of the person (in our case 4 m/s);
being his final velocity (in our case 15 m/s);
and the difference 
the time the change in velocity took (in our case 1 second).
Therefore in our example, the person's acceleration is:
Like I said. It’s annoying. But I appreciate you doing this for new people.
