00:01
In this problem, a rectangular tank with base of four feet by five feet at a height of four feet, full of water.
00:06
They've not given us a figure, but we'll look at some schematic of this.
00:09
The water weighs 62 .4 pounds per cubic foot.
00:13
The question is how much work needs to be done in pumping the water out of the top edge of the tank so that the tank is half empty and the tank is fully empty.
00:24
That's a and b.
00:25
Now if you look at the tank's dimensions here, so let's assume that this is 5, this is 4, and this is 4.
00:31
In this direction, it's x, in this direction, it's z, and let's assume that this direction here is y.
00:37
The y is the height, which corresponds to 4, and therefore from the top edge, if you start emptying it, it will fully empty downwards, or if you can empty upwards, whichever direction you're thinking about.
00:48
But it's essentially that the height of the water level, that's what is going to change with respect to y...