Physics

posted by .

A rectangle has a length of 2d and a height of d. Each of the following three charges is located at a corner of the rectangle: +q1 (upper left corner), +q2 (lower right corner), and -q (lower left corner). The net electric field at the (empty) upper right corner is zero. Find the magnitudes of q1 and q2. Express your answers in terms of q.

  • Physics -

    THere are a number of ways to do this, some more difficult than others.
    If you note the E due to q2 is upward, and the E due to q1 is horizontal, then the E due to q3 must add to zero. That is, the E due to q3 in the horizontal direction must be equal and opposite to q1, and The E due to q3 in the vertical must be equal and opposite to Q2

    So dealing with q3 first.
    letting o be the distance of the horizontal (o^2=d^2+4d^2=5d^2; or o=dsqrt5)
    Ehorizontal=k q/o^2*2d/o=2kqd/o^3
    Evertical= kq/o^2*d/o=kqd/o^3

    So now setting the vertical of q3 equal to the vertical of q2
    k*q2/d^2=kqd/o^3

    q2=q (d/o)^3=q(d/dsqrt5)^3=q/5sqrt5

    now, setting the horizontal of q3 equal to the horizontal of q1
    kq1/4d^2=2kqd/o^3
    q1=8q (d/o)^3 and you can finish the algebra.

    Check all this math, I did it in my head keying it in.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    There are two +q charges and two -q charges on the corners of a square of size a. Left upper corner= +q charge, right upper corner= -q charge, left lower corner= -q charge, and right lower corner= +q charge. Compute the net force on …
  2. Physics

    At each corner of a square of side script i there are point charges of magnitude Q, nQ, mQ, and 4Q, where n = 3 and m = 3. Determine the force on the charge mQ due to the other three charges. (mQ is on the bottom right corner, nQ is …
  3. Physics 1112 Electric charge

    As shown in the figure, a square has sides of 8.0 cm with a charge of +6.0 µC at one corner (a) and with charges of -2.0 µC at the remaining three corners (b, c, and d). The figure is just a square with no measurements. Corner a …
  4. physics

    A rectangle has a length of 2d and a height of d. Each of the following three charges is located at a corner of the rectangle: +q1 (upper left corner), +q2 (lower right corner), and -q (lower left corner). The net electric field at …
  5. Physics Superpostion Principle

    four charged particles are placed so that each particle is at the corner of a square. the sides of the square are 15 cm. the charge at the upper left corner is +3.0 microcoulombs, the charge at the upper right corner is -6.0 microcoulombs, …
  6. Physics

    Three charges are located at the corners of a rectangle as follows: Charge A: lower left corner, -3.0 μC Charge B: upper left corner, -6.1 μC Charge C: upper right corner, +2.7 μC The distance between A and B is 0.16 m and …
  7. Physics

    In the rectangle in the drawing, a charge is to be placed at the empty corner to make the net force on the charge at corner A point along the vertical direction. What charge (magnitude and algebraic sign) must be placed at the empty …
  8. Physics

    I don't really know where to start on the problem. Would I use V = k(q/r)?
  9. Physics

    Three charged particles are arranged on corners of a square as shown in the figure below, with charge -Q on both the particle at the upper left corner and the particle on the lower right corner, and charge +2Q on the particle at the …
  10. Physics

    Four charges are located at the four corners of a square of side b: Q1 = 3 nC at the top right corner, Q2 = -4 nC at the bottom right corner, Q3 = 5 nC at the top left corner, Q4 = 7 nC at the bottom left corner. What is the electric …

More Similar Questions