00:01
Hello.
00:03
So for this problem, we are given the velocity vector of a fluid as v is equal to minus y square i minus 6xj.
00:14
And then we are told to find the equation of streamline at the point 1 -1.
00:30
Generally, we know that this velocity vector can be written in this form.
00:39
And so when we look at this, we can simply say comparing the problem.
00:43
We were given and this general form of the velocity vector i can say therefore that u is equal to minus y squared and v is equal to minus 6 x now what is the equation of a streamline the equation of a streamline is simply the x over u is equal to the y over v which is equal to the z over w now because we have a two -dimensional problem here in terms of only u and v we will not have anything to do with this term.
01:33
And so i can take just the first two terms and i can say that for this are streamline, we'll have this equation and putting in what the values of u and v are, i will simply have the x over minus y squared is equal to the y over minus 6x.
01:57
Now when i simplify this by cross multiplying, i will get 6.
02:02
6x the x is equal to y squared the y i've cancelled the minus because it's on both sides now what do i do i simply because this is a separable variable differential equation ordinary differential equation actually so this is a separable variable and i've already separated the variables so what i simply have to do is to integrate both sides and so i'll put the integral for 6x the x is equal to the integral for y squared the y.
02:46
When i perform this integral here, i'll get 6x squared over 2 is equal to y cube over 3 plus c...