Electric field at a point on a contour line (1 Viewer)

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Hi guys!

In this question I am asked to "Calculate the size of the electric field at k". See image at: http://capa-new.colorado.edu/msuphysicslib/Graphics/Gtype54/prob04a_threeqcontour.gif

Note: although the picture states "Volts", everything is actually measured in kV.

2. Relevant equations
∆V = Ed

3. The attempt at a solution
I tried to set V = -5kV, and solving for E by measuring the distance from point k to Q1, but this doesn't seem to work. Will I have to do this for all three charges? Or, am I totally off base and should be approaching it from a different angle?

Thanks for your help!

-Max
 

AEM

361
0
Hi guys!

In this question I am asked to "Calculate the size of the electric field at k". See image at: http://capa-new.colorado.edu/msuphysicslib/Graphics/Gtype54/prob04a_threeqcontour.gif

Note: although the picture states "Volts", everything is actually measured in kV.

2. Relevant equations
∆V = Ed

3. The attempt at a solution
I tried to set V = -5kV, and solving for E by measuring the distance from point k to Q1, but this doesn't seem to work. Will I have to do this for all three charges? Or, am I totally off base and should be approaching it from a different angle?

Thanks for your help!

-Max
As I figure it the difference between each contour line is 1 KV. Since

[tex] E = -\frac{\Delta V}{d} [/tex]

you want to measure the perpendicular distance from k to the nearest contour line and express E as so many volts per meter (or what ever distance unit you desire). Note the minus sign in my equation. That implies something about the direction of E.
 

The Physics Forums Way

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving
Top