00:02
So this is newton's law of cooling and 75 degrees is the ambient temperature.
00:08
This is how long it takes to reach that.
00:10
These are always connected.
00:12
And what it is internally is 165.
00:17
So when we keep, we have to find k first.
00:21
So that's what we're actually doing right now.
00:24
So 145 minus 75 is 70.
00:28
And our goal is to solve for.
00:31
K.
00:32
So i'm going to do 70 divided by 165 equals e to the 30k.
00:37
Can't solve it in exponential form.
00:40
So we're going to solve it in log form.
00:42
And because it's base e, we use the natural log.
00:48
So that equals 30k.
00:51
Now we know we're going to divide by 30.
00:55
So we're going to get k equals.
00:57
And we're going to do it on here, the natural log of 70 divided.
01:05
By 165.
01:08
And that's going to give us, oh, not that.
01:13
70 divided by 165 gives us this number, but don't forget we need to divide by 30, that 30 minutes.
01:20
So we end up getting negative 0286.
01:24
So k equals negative 0286.
01:27
We always use four places.
01:29
So the temperature after 50 minutes is going to, we're going to use this formula, and we still, the internal temperature is still 165.
01:40
K is negative 0 .286 times 50 minutes plus 75.
01:48
So we're going to use this again, and we're going to use this one right here, e to the x...