Uniform electric field in a triangular arrangement

[larkinfan11]

Homework Statement

The drawing shows a uniform electric field that points in the negative y direction; the magnitude of the field is 1600 N/C.

http://www.webassign.net/CJ/p19-32.jpg

a) Determine the electric potential difference VB - VA between the points A and B.
The answer here is 0 V.

(b) Determine the electric potential difference VC - VB between the points B and C.
V

(c) Determine the electric potential difference VA - VC between the points C and A.
V

Homework Equations

delta(V)=-Ed

The Attempt at a Solution

For A, delta(V)= -(1600N/C)(.06m)- -(1600N/C)(.06m)= 0V

For B, I tried delta(V)= -(1600)(.08)- -(1600)(.08)=0V which is an incorrect answer according to my online submission.

C hasn't been attempted yet, because I'm going to need to make sure I'm doing this correctly.

I'm not sure how to determine the different potentials when I have no values for the point charges... Can anyone offer some assistance? Not looking for answers, just guidance that will get me on my way. Thanks!

 

[larkinfan11]

Can anyone help me out here?

 

[3trQN]

You used 0.8 twice in B) which would put both charges in the same place (in y).

You want their separation, the amount the E field drops off with that distance. Which is linear according to the equation shown.

(i think, I am no physicist)

 

[larkinfan11]

I figured that using the 0.8 twice is part of my problem, but I'm honestly lost as to how to determine Vb and Va, etc. without any information about a charge at each of those points, let alone calculating delta(v) between those without any of that information. If someone could give me a clue on that, I can handle the rest. I've spent hours on this problem and I don't even think I'm looking at it correctly anymore.

 

[jo18bandgirl]

E=(delta(V)/delta(s)) where s is the distance between the points, it works for part b but i don't know about part c yet

you switch it around to get delta(V)=E*delta(s)