- #1

isukatphysics69

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## Homework Statement

A solid is generated by revolving region bounded by y=(1/2)x^2 and y=12 about the y axis. A hole centered along the axis of revolution is drilled through this solid so that 1/4 of the volume is removed. find the diameter of the hole.

## Homework Equations

y=(1/12)x^2 y = 12

shell method integral

## The Attempt at a Solution

i figured out the boundries are x=0 to x=12 and integrated using the shell method and got the answer of the total volume as 864*pi. I divided that by 4 and got 216*pi as the area that needs to be removed but now i am stuck and don't know how to figure out the diameter of the hole! [/B]