a 2.2nC charge is at the origin and a -6nC charge is at 1.2cm.
a) at what x- coordinate could you place a proton so that it would experience no net force?
b) would the net force be zero for an electron placed at the same position? explain.

Question

a 2.2nC charge is at the origin and a -6nC charge is at 1.2cm. 
a) at what x- coordinate could you place a proton so that it would experience no net force?
b) would the net force be zero for an electron placed at the same position? explain.

anonymous · Answer

i got a...0.43cm and -1.5cm. i don't know how to figure out b. does it have to do with mass? i never had to use mass in finding a though...

jamesj · Answer

Whatever the point is, the net electric field there is zero.  In which case, it won't matter what test charge you point at that point.  The net force the charge will experience, whatever the magnitude and sign of that charge, must be zero.