Posted by Cube on September 10, 2002 at 17:09:58:
In Reply to: Re: decibals and Logarithms posted by Tootsie on September 10, 2002 at 15:07:28:
It appears you are getting your minuses and divisions mixed up.
Though you subtract exponents from each other it is still a process of division. Use your calculator to check.
It may be easier to thing of this process if in terms of a dollar if you forget it again.
100= 100 pennies = 10^2 = log 100 = 2
so 100 is 100 times bigger than a penny.
A dime is 1 tenth of a dollar. 10 cents = .10= 10/100 and log .1 = -1
so your problem
10^12/10^8= 10^4 = 10,000 and log 10,000 = 4
so the thunder is 10,000 times louder than the sound of traffic.
: : : Is it really a matter of 10^12 - 10^8 = 10^4?
: : First, look at that again!
: : Is 2^5 - 2^2 = 2^3 ?
: No, it's not. But I feel very stupid today. What are the next steps? I can't recall?