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armolinasf
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Homework Statement
There's a cone with height 12 feet and radius 4 feet. It is filled with water to a depth of 9 feet. Find the work required to pump the water over the top. The density of water is 62.4lbs/ft^3
work=force*distance & force=volume*density
The Attempt at a Solution
F=pi(r^2)*62.4 and r=(12-y)/3 by similar triangles
the distance should be 12-y
Putting this together, my integral looks like this:
62.4[tex]\pi[/tex]/9 [tex]\int^{9}_{0}[/tex](12-y)[tex]^{3}[/tex]dy
evaluating gives 37491 ft-lbs, but the answer in my book is 27788 ft-lbs
If someone can point out where I'm going wrong, it would be much appreciated.