Homework Help: Physics

Posted by emily on Thursday, December 1, 2011 at 4:06pm.

A radio set at a sound level of 20 dB is suddenly increased to 80 dB. how many more time greater is the pressure amplitude at 80 dB? I do not know what to do please help

Physics - Henry, Friday, December 2, 2011 at 9:10pm
20Log(Vo/Vi) = 20db,
Log(Vo/Vi) = 1,
Vo/Vi = 10^1 = 10. = Voltage ratio.

20Log(Vo/Vi) = 80db,
Log(Vo/Vi) = 4,
Vo/Vi = 10^4 = 10,000.

Ratio = 10^4 / 10^1 = 10^3 = 1,000.

Therefore, the signal level at 80db is
1,000 times the signal level at 20db.

Answer this Question

Related Questions

Physics SOUND - What is the resultant sound level when an 80-dB and an 85-dB ...
PreCalc - The decibel (dB) is defined as dB= 10log (P2/P1), where P2 is the ...
physics - The sound intensity level at a concert increases from 85 dB to 94 dB ...
Physics - Please Help - A 60 year old person has a threshold of hearing of 81.0 ...
Physics of Sound - For a speaker whose sound power output is 140 dB, the ...
physics - Factory Worker A is exposed to a sound of a constant intensity of 6.30...
physics - A grade-school teacher insists that the the overall sound level in his...
physics - In a pig-calling contest, a caller produces a sound with an intensity ...
Physics - You are trying to overhear a juicy conversation, but from your ...
physics - A loudspeaker is placed between two observers who are 111 m apart, ...

For Further Reading

First Name:
School Subject:
Answer: