Comparing Jackson 6.2 and 5.26 Solutions

[ber70]

Jackson 2nd editon 6.2 and 3rd edition 5.26 are same questions but given solutions in problems are different. 2nd edition includes c2 (c*c), 3rd edition includes nü/4pi(=c). Which is true and why?

 

[Ben Niehoff]

Jackson 2nd edition is written entirely using Gaussian units. Jackson 3rd edition is written using SI units for the earlier chapters, and Gaussian for the later (as indicated in the upper margin of the page).

Check if the formulas come out the same after accounting for the difference in units. If they're still off by a factor of c, then check the errata, maybe?

 

[ber70]

errata link
http://www.wiley.com/college/phy/jackson30932X/ce3errat.pdf

there is no error in this problem and nü/4pi equal c. I am not mistake.