00:01
So this question we have a tank, which is an inverted right rectangular pyramid.
00:05
So it's got a square on top.
00:07
That's the base.
00:09
And then we have that these points meet down here.
00:18
And we have that it has a width of two feet, a depth of two feet and a height of three feet.
00:25
So this is two feet.
00:27
This is two feet.
00:30
And this is three feet.
00:32
And then we have to pump, so this is full of oil with a weight density, row is 50 pounds per cubic foot, and we have to pump it up to a level of one foot above the tank.
00:54
So let's consider a coordinate system where we have x equals zero here, and x is increasing this way, so this is x equals three.
01:05
Then the increment of the work at a position x is going to be, so the height that you have to pump it is x plus one, the weight density is row, and then you want the increment of the volume, which is the area at the position x times dx.
01:29
So this is row x plus one times...