Answer:
The water required to pump all the water to a platform 2 feet above the top of the pool is is 6061310.32 foot-pound.
Explanation:
Given that,
Radius = 21 feet
Height = 10 feet
Weighing = 62.5 pounds/cubic
Work = 4329507.37572
Height = 2 feet
Let's look at a horizontal slice of water at a height of h from bottom of pool
We need to calculate the area of slice
Using formula of area
![A=\pi r^2](https://tex.z-dn.net/?f=A%3D%5Cpi%20r%5E2)
Put the value into the formula
![A=\pi\times21^2](https://tex.z-dn.net/?f=A%3D%5Cpi%5Ctimes21%5E2)
![A=441\pi\ feet^2](https://tex.z-dn.net/?f=A%3D441%5Cpi%5C%20feet%5E2)
Thickness of slice ![t=\Delta h\ ft](https://tex.z-dn.net/?f=t%3D%5CDelta%20h%5C%20ft)
The volume is,
![V=(441\pi\times\Delta h)\ ft^3](https://tex.z-dn.net/?f=V%3D%28441%5Cpi%5Ctimes%5CDelta%20h%29%5C%20ft%5E3)
We need to calculate the force
Using formula of force
![F=W\times V](https://tex.z-dn.net/?f=F%3DW%5Ctimes%20V)
Where, W = water weight
V = volume
Put the value into the formula
![F=62.5\times(441\pi\times\Delta h)](https://tex.z-dn.net/?f=F%3D62.5%5Ctimes%28441%5Cpi%5Ctimes%5CDelta%20h%29)
![F=27562.5\pi\times\Delta h\ lbs](https://tex.z-dn.net/?f=F%3D27562.5%5Cpi%5Ctimes%5CDelta%20h%5C%20lbs)
We need to calculate the work done
Using formula of work done
![W=F\times d](https://tex.z-dn.net/?f=W%3DF%5Ctimes%20d)
Put the value into the formula
![W=27562.5\pi\times\Delta h\times(10-h)\ ft\ lbs](https://tex.z-dn.net/?f=W%3D27562.5%5Cpi%5Ctimes%5CDelta%20h%5Ctimes%2810-h%29%5C%20ft%5C%20lbs)
We do this by integrating from h = 0 to h = 10
We need to find the total work,
Using formula of work done
![W=\int_{0}^{h}{W}](https://tex.z-dn.net/?f=W%3D%5Cint_%7B0%7D%5E%7Bh%7D%7BW%7D)
Put the value into the formula
![W=\int_{0}^{10}{27562.5\pi\\times(10-h)}dh](https://tex.z-dn.net/?f=W%3D%5Cint_%7B0%7D%5E%7B10%7D%7B27562.5%5Cpi%5C%5Ctimes%2810-h%29%7Ddh)
![W=27562.5\pi(10h-\dfrac{h^2}{2})_{0}^{10}](https://tex.z-dn.net/?f=W%3D27562.5%5Cpi%2810h-%5Cdfrac%7Bh%5E2%7D%7B2%7D%29_%7B0%7D%5E%7B10%7D)
![W=27562.5\pi(10\times10-\dfrac{100}{2}-0)](https://tex.z-dn.net/?f=W%3D27562.5%5Cpi%2810%5Ctimes10-%5Cdfrac%7B100%7D%7B2%7D-0%29)
![W=4329507.37572](https://tex.z-dn.net/?f=W%3D4329507.37572)
To pump 2 feet above platform, then each slice has to be lifted an extra 2 feet,
So, the total distance to lift slice is (12-h) instead of of 10-h
We need to calculate the water required to pump all the water to a platform 2 feet above the top of the pool
Using formula of work done
![W=\int_{0}^{h}{W}](https://tex.z-dn.net/?f=W%3D%5Cint_%7B0%7D%5E%7Bh%7D%7BW%7D)
Put the value into the formula
![W=\int_{0}^{10}{27562.5\pi\\times(12-h)}dh](https://tex.z-dn.net/?f=W%3D%5Cint_%7B0%7D%5E%7B10%7D%7B27562.5%5Cpi%5C%5Ctimes%2812-h%29%7Ddh)
![W=27562.5\pi(12h-\dfrac{h^2}{2})_{0}^{10}](https://tex.z-dn.net/?f=W%3D27562.5%5Cpi%2812h-%5Cdfrac%7Bh%5E2%7D%7B2%7D%29_%7B0%7D%5E%7B10%7D)
![W=27562.5\pi(12\times10-\dfrac{100}{2}-0)](https://tex.z-dn.net/?f=W%3D27562.5%5Cpi%2812%5Ctimes10-%5Cdfrac%7B100%7D%7B2%7D-0%29)
![W=1929375\pi](https://tex.z-dn.net/?f=W%3D1929375%5Cpi)
![W=6061310.32\ foot- pound](https://tex.z-dn.net/?f=W%3D6061310.32%5C%20foot-%20pound)
Hence, The water required to pump all the water to a platform 2 feet above the top of the pool is is 6061310.32 foot-pound.