Field Transformations work forwards but not backwards?

[Physics_5]

I got the right answer for this example problem going from reference frame A to B but when I use those fields to go back from B to A I don't get the same magnetic field I started with.

Do field transformations only work one way? Surely not? I don't see how forces could be the same if this were the case

Link to example problem: http://imgur.com/GCQeayW

 

[dauto]

You must have made a mistake because the field transforms work both ways. Hard to help you though since you couldn't be bothered to tell us what calculations you've made so far...

 

[dauto]

After looking at the example you linked I realize that the transformations you're using are the the low speed approximations. These are not exact. That might explain any discrepancies you may have found. Hard to tell because, again, you did not give us much explanation about the problem you're confronted with.

 

[Physics_5]

Sorry for not posting calculations. I just read the next section and it addressed my concern. My reasoning was not wrong. The problem is that I was using the Galilean transformation equations, which I did not know we're based on the approximation v^2/c^2 = 0. Thanks everyone for helping.