new to the site and I was wonderin if I could gets some info or feedback. I'm trying to find the cross-sectional area for the object posted. I have found one equation A=.785d^2 while d= large circular diameter - smaller circular diameter not sure if this would be right. I also need an equation for a changing diameter. What the object is suppose to look like is the bottom of a hole with a stopper rod plugging it from the other side. And with the stopper rod opening the cross-sectional area changes. So if I could gets some feedback that would be great. Thx

Craig[attachmentid=896]