Problems with dB

  • Thread starter stumped23
  • Start date
  • #1
3
0
'The intensity level of sound in a factory is 93.0 dB when all seven of its machines are working. If four machines are shut down for maintenance, what is the intensity level of the sound from the remaining machines? Assume that all seven machines are identical.'

I know the answer is not just 3/7*93 as dB are similar to the richter scale. I found http://en.wikipedia.org/wiki/Decibel" [Broken] and am trying to apply the third formula under 'Defintion' but to little success. I'm very confused.

Could anyone explain a little clearer exactly what the dB is?
 
Last edited by a moderator:

Answers and Replies

  • #2
HallsofIvy
Science Advisor
Homework Helper
41,833
964
Reverse your formula: all 7 machines are 7/3 as loud as only 3 so you must have 93.0= 10log((7/3)X) where X is the intensity of 3 machines.
 

Related Threads on Problems with dB

  • Last Post
Replies
2
Views
8K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
4
Views
4K
  • Last Post
Replies
2
Views
747
  • Last Post
Replies
8
Views
2K
  • Last Post
Replies
0
Views
1K
  • Last Post
Replies
1
Views
30K
  • Last Post
Replies
3
Views
17K
Top