- #1
issacnewton
- 1,000
- 29
Hello
I am solving some problems from "Intro to EM" by David Griffiths ( third edition)
Problem 2.26 ( attached file 2.26.jpg) and I have also attached the solution from the solution
manual (griffiths-2.26.jpg). For both part a and b I am getting different answer.
I have chosen vertex as the origin and the axis of the cone as the positive z-axis.
The bottom of the cone is toward positive z axis. Now any differential area element on the cone would be (using cylindrical coordinates) , x*d(phi)*dz , where x is the perpendicular
distance of the area element from the z-axis. But for this geometry, x=z for any point on the
cone , so dz = dx. The distance r of this area element from the origin(vertex) would be
sqrt(2)*x. I am supposed to use the formula (formula.jpg).
Why are my solutions not working ? Or is the instructor's solution manual incorrect ?
Regards
I Newton
I am solving some problems from "Intro to EM" by David Griffiths ( third edition)
Problem 2.26 ( attached file 2.26.jpg) and I have also attached the solution from the solution
manual (griffiths-2.26.jpg). For both part a and b I am getting different answer.
I have chosen vertex as the origin and the axis of the cone as the positive z-axis.
The bottom of the cone is toward positive z axis. Now any differential area element on the cone would be (using cylindrical coordinates) , x*d(phi)*dz , where x is the perpendicular
distance of the area element from the z-axis. But for this geometry, x=z for any point on the
cone , so dz = dx. The distance r of this area element from the origin(vertex) would be
sqrt(2)*x. I am supposed to use the formula (formula.jpg).
Why are my solutions not working ? Or is the instructor's solution manual incorrect ?
Regards
I Newton