- #1
mborn
- 30
- 0
Five equal negative point charges (-q) are placed symmetrically around a circle of radius R. Calculate the electric field at the center of the circle.
My Answer:
Each one will be place 72 degrees from the other one (360/5),
Each field line is directed toward the center (charges are negative),
I had;
E_x = (kq/R^2)[-cos 72 + cos 36 + cos 36 - cos 72]
= kq/R^2
E_y = (kq/R^2)[- sin 72 - sin 36 + sin 36 - sin 72]
= 0 N/C
My book says that both E_x and E_y are zero, What did I do that was wrong?
mbron
My Answer:
Each one will be place 72 degrees from the other one (360/5),
Each field line is directed toward the center (charges are negative),
I had;
E_x = (kq/R^2)[-cos 72 + cos 36 + cos 36 - cos 72]
= kq/R^2
E_y = (kq/R^2)[- sin 72 - sin 36 + sin 36 - sin 72]
= 0 N/C
My book says that both E_x and E_y are zero, What did I do that was wrong?
mbron