00:01
Okay, so in this problem we just need to apply the equation of continuity, which says that the initial speed, oops, it should be a v.
00:12
Let's put here, the initial speed times the initial cross -sectional area is going to be equal the final speed times the final cross -sectional area.
00:29
In this case, we have an area.
00:32
That is circular.
00:36
So let's see we have that our area is going to be a pi times the radius square.
00:45
Okay, so now that we have the equation of continuity we can answer the problem.
00:55
So if we want to calculate the exit speed, so the final speed, we can say that the final speed it's going to be equal the initial speed times the initial cross -sectional area divided by the final cross -sectional area but who is a i and a f so let's put in here we know that the initial area is going to be, let's see, pi times 0 .8, which is the first radius, square.
01:41
And the final area is going to be 20 pi that multiplies 0 .1 square.
01:58
We have to multiply by 20.
02:03
We have to multiply has 20 circular openings...