E-Fields Question

  • #1
1. Homework Statement
Two charges, charge one is +Q and charge two +2Q, are fixed in a plane along the y axis of an x-y coordinate plane. Charge one is at point (0,a) and Charge two is at the point (0,2a).
(a) Is there any portion of the y-axis in which the total electric field is zero? If so, where?
(b) If a small negative charge, -q, of mass m were placed at the origin, determine its initial acceleration (magnitude and direction).


2. Homework Equations

E1=E2
F=ma
E=F/q
E=1/4pi(epsilon not)xQ/r^2


3. The Attempt at a Solution

For (a), there will always be an e-field along the y-axis except for a point in between the two charges. I am having trouble finding that point, though. I set the two e-fields equal to each other, but was unsure of what to put as the radius for each.

For (b) I used F=ma and then plugged in F=Eq to get a=Eq/m. My final answer was (-1/4pi(epsilon not)x(Q/a^2+Q/2a^2)xq)/m.
 

Answers and Replies

Related Threads on E-Fields Question

  • Last Post
Replies
8
Views
2K
  • Last Post
Replies
10
Views
4K
  • Last Post
Replies
7
Views
869
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
2
Views
520
Replies
1
Views
2K
  • Last Post
Replies
6
Views
1K
Replies
8
Views
661
Replies
1
Views
1K
Top