Answer Happy

4.22* The proof in Example 4.5 (page 119) that the Coulomb force is conservative is considerably simplified if we evaluate 5 x F using spherical polar coordinates. Unfortunately, the expression for 1 x F in spherical polar coordinates is quite messy and hard to derive. However, the answer is given Problems for Chapter 4 153 inside the back cover, and the proof can be found in any book on vector calculus or mathematical methods. 15 Taking the expression inside the back cover on faith, prove that the Coulomb force F = yf/r2 is conservative.