Source: Physics and Scientists for Engineers, Ch. 24 #7 A cone of radius R and height h sits on a horizontal table. A uniform electric field parallel to the table penetrates the surface of the cone. What is the flux entering the cone? Diagram: (N.B. the dots in the cone are just to give it shape) E -->.../.\ -->../...\ -->./.....\ <---- cone -->/____\___________ <- table The back of the book gives an answer of flux_entering=EhR, which I don't get. I don't see why there isn't a pi in that answer, since the surface area of the face of the cone that's being penetrated certainly does have a pi in it. My attempt at a solution yields flux_entering=pi*E*h*r/3. Hah, it's close... but not. EDIT: The field is uniform, I forgot to mention that.