00:01
There, so for this problem, we have the situation that we are shown in this figure.
00:07
So we need to estimate the value of the directional derivative of the pressure function at kearney in the direction of coo city is labeled in here.
00:20
We have co's city right here and the other city, which is kearney.
00:30
Nebraska and the distance between this two is 300 kilometers so that's what we need to estimate the value of the directional derivative okay so we know that the pressure p we are given that value that is at the value is 972 as you can see from the finger then this in units of megabars, milibars, sorry.
01:14
And then the distance between these two, that we're going to call the distance d, is 300 kilometers.
01:22
Now, the directional derivative is the rate at which the function changes at a point in the given direction, okay? so in the given problem, we need to estimate the directional derivative of pressure function at the label k in the direction of s by the average rate of change of pressure between the points where the red line in here intersects, oh, let me period in red, the contour lines closest to k.
01:55
So now extend the red line slightly at the left in the direction of s.
02:01
So the pressure changes from, as you can see from the figure, this corresponds from 1 ,000, as you can see from the figure, this corresponds in here to this point right here...