Using the Calculator on the exam!?
Hey All,
Quick question:
I am in Black Spectacles practice exam right now playing around with the resources and getting familiar with using the calculator. I am having trouble understanding how the "log" button works?! This should be so simple yet I can not figure out how to get the correct answer using the calculator.
Im practicing with example problem 19.2 in the Ballast 5.0 book. The questions is:
A room in an office contains eight machines, each of which produces 73dB of sound. What is the overall sound level?
The equation to use is IL(total) = IL(source) + 10log(n) ... so plugging in the numbers from the example problem I get 73dB + 10log(8)
The answer in the book is 82dB.
When I use the calculator and type 73 + 10log8 it only equals 81 ?!?! How to use use the "log" command properly!? Someone please help me solve this silly thing?! I feel like a total idiot.

I cam across this recently in my studies, but it didn't cause me to flinch. I'm not sure what you are doing wrong, make sure you are closing parentheses correctly (some calculators don't follow the order of operations correctly). If all else fails, check your work on Google.
log(8) = 0.903
10 * log(8) = 9.03
73 + 10 * log(8) = 82.03
the answer is 82 dB
Please sign in to leave a comment.
Comments
4 comments