Why Did I Misinterpret the Direction of E in Charged Particles?

[hoseA]

http://img147.imageshack.us/img147/264/chargedparticlesii6fe.png

In the above question I thought the direction of E would be to the right. Apparently that's wrong... why?

 

[quasar987]

The field of a negative charge points towards it and that of a positive charge points away from it. The field in region III is the sum of the fiels produced by both charge. Knowing how the field varies with charge magnitude and distance (coulomb law), what can you conclude about which field, btw that of the + charge and that of the - charge, dominates in region III? Show us some work.

 

[hoseA]

The field of a negative charge points towards it and that of a positive charge points away from it. The field in region III is the sum of the fiels produced by both charge. Knowing how the field varies with charge magnitude and distance (coulomb law), what can you conclude about which field, btw that of the + charge and that of the - charge, dominates in region III? Show us some work.

After reading over the chapter I finally understand what that means. So it's pointing left. I think it's quite obvious from the drawing such that calculations are unecessary. Thanks for the help. I FINALLY understand what "The field of a negative charge points towards it and that of a positive charge points away from it" means. I'm just a little slow .

Thanks for the help .

 

[jtbell]

I thought the direction of E would be to the right. Apparently that's wrong... why?

Why did you think it would be to the right?

 

[hoseA]

Why did you think it would be to the right?

i assumed it would be to the right since i had a stupid preconception that protons move towards electrons and electrons were somehow fixed. For some reason I didn't consider the point p... rather just the two charges. Bottomline: i didn't have a good understanding since I didn't read the chapter 'til a few hrs. ago.