0:00
Hi there.
00:01
So for this problem, we are told that we have a register of, let's label it as beta 1 of 127 decibels, and it is placed at a distance of 2 .2 meters.
00:17
Let's label this as the distance, the 1, 2 .2 meters, okay? now, the intensity of the reference level recorded at the tremendous level, we are, given that value, so the reverse intensity is the usual value of 1 times 10 to the minus 12 webs per meter square.
00:40
Once we have this, the question is the distance, let's look at us the distance, the 2, such that the cell level it is equal to 89 decibels.
00:53
So the first equation that we are going to start with this problem is the equation that the cell level, it is defined as 10 times the logarithm, of course in base 10, of the ratio between the intensity and the intensity sub -zero.
01:11
And we are going to use these expressions in order to obtain the intensity at this point.
01:23
Okay.
01:25
And once we have the intensity at that point, we know that the intensity, the ratio between the intensity is the intensity 1 divided by the intensity 2 equals to the distance d2 divided by the distance d1 and that to the square.
01:41
So we need to know this ratio in order to solve for the distance d2 that we are asked for this problem.
01:48
Okay, so let's start by calculating the intensity i want because remember that we are given in the zone level, no intensity.
01:58
This.
01:58
So let's solve in here.
01:59
So we can pass this to decide to divide beta.
02:03
And then that will be then the logarithm of this ratio.
02:07
And then we apply the inverse function of the logarithm base then is that we just do it like this.
02:17
Okay...