I was just looking over my notes and I do not understand this question entirely
A cone with height 10ft and top radius 5ft is filled with oil which weighs 57lb/ft^3. find work done in pumping out the oil.
I know that the interval being sliced is [0,10] because the oil fills the entire tank.
I also understand why the the distance is (10-y)
What I do not understand according to my notes is where (y^2) comes from. Or where the radius comes into play?
If it is coming from the formula for a cone 1/3pi*r^2 then why does my notes say the final answer is
I thought it should be