Find the Electric Field at a midway point

In summary, the problem is finding the electric field at a point midway between two charges of +30.0 x 10^-9C and +60.0 x 10^-9C separated by a distance of 30 cm. Using the formula E=k(Q/r^2), the electric field at this point is calculated to be 3000 N/C and 6000 N/C for the charges separately. However, when added together, the total electric field is incorrect at 9000 N/C. The correct approach is to subtract the electric fields, resulting in 3000 N/C. It is important to draw a diagram and consider the directions of the fields produced by each charge.
  • #1
1126
7
0
The problem is:
Find the electric field at a point midway between two charges of +30.0 x 10^-9C and +60.0 x 10^-9 C separated by a distance of 30 cm.


I used E=k (Q/r^2)
My attempt is:

E=(9x10^9)(30.0 x 10^-9C)/(.3m^2)
E=3000 N/C

E=(9x10^9)(60.0 x 10^-9 C)/(.3m^2)
E=6000 N/C

added they are 9000 N/C. I am fairly certain this is incorrect, but I do not understand the material. I really have no idea why or how to go about finding the correct answer. Please help!
 
Physics news on Phys.org
  • #2
I think you might want to try subtracting them like 6000-3000=3000.
I think that electric fields go away from positive charges
 
  • #3
I still don't really understand. Is .3m really the right radius? It's the distance between the charges, but I'm not sure if it's the right radius to use. Any suggestions? :/
 
  • #4
Always draw a diagram. If the two charges are separated by 30 cm, how far is the mid point from each charge? Pay attention to the directions of the fields that each charge produces at the given location.

attachment.php?attachmentid=44425&stc=1&d=1330304042.gif
 

Attachments

  • Fig1.gif
    Fig1.gif
    1.1 KB · Views: 1,602
  • #5
Thank you so so so much! that was so helpful! I think I solved it correctly now. :) thanks so much!
 

What is the concept of "Find the Electric Field at a midway point"?

The concept is used in physics to determine the electric field at a point that is equidistant from two or more sources of electric charge.

How is the electric field calculated at a midway point?

The electric field at a midway point is calculated by taking into account the magnitude and direction of the electric fields created by each source of charge, and summing them together using vector addition.

What information is needed to find the electric field at a midway point?

To find the electric field at a midway point, you will need the magnitudes and directions of the electric fields created by each source of charge, as well as the distances between the sources and the midway point.

What is the significance of finding the electric field at a midway point?

Finding the electric field at a midway point can provide valuable information about the distribution of electric charge and the resulting electric field in a given system. It can also be used to calculate the force exerted on a charged particle at that point.

What are some real-world applications of finding the electric field at a midway point?

One common application is in the design of electrical circuits, where the electric field at a midway point can help determine the strength and direction of the current flow. It is also used in the analysis of electric fields in nature, such as in the Earth's atmosphere during a thunderstorm.

Similar threads

  • Introductory Physics Homework Help
Replies
5
Views
707
  • Introductory Physics Homework Help
Replies
10
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
715
  • Introductory Physics Homework Help
Replies
2
Views
984
  • Introductory Physics Homework Help
Replies
1
Views
933
  • Introductory Physics Homework Help
Replies
3
Views
804
  • Introductory Physics Homework Help
Replies
11
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
717
  • Introductory Physics Homework Help
Replies
4
Views
1K
Back
Top