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Homework Help: How to find potential difference between 2 parallel deflection plates

  1. Apr 28, 2013 #1
    1. The problem statement, all variables and given/known data
    Describe by pointform how to find potential difference between parallel deflection plates, ΔV₂ = ?
    You don't have to solve.

    ΔV1 = 1.38 kV
    Δx = 5 cm
    Δy = 0.49 cm
    r = 5.2 cm
    q = 1.6 x 10^-19 C
    m = 9.11 x 10^-31 kg
    k = 9 x 10^9 Nm^2/C^2

    2. Relevant equations
    ε = ΔV/d
    W = ΔEe = qΔV
    V = kq/r
    Fe = kq1q₂/r^2
    Fe = qε
    Ee = kq1q₂/r

    3. The attempt at a solution
    i don't have the velocity so i don't know how. If i did have velocity i would find time.

    Attached Files:

    Last edited: Apr 28, 2013
  2. jcsd
  3. Apr 28, 2013 #2
    I am on thin ice here, but its ok I am happy making a fool out of myself

    Don't you use the potential between the cathode and the anode and the charge on the electron to calculate the energy gained in traversing the first part of your diagram and equate this to the kinetic energy to solve for the velocity as you leave the slit in the vertical anode

    1/2 mv^2=eV
    Last edited: Apr 28, 2013
  4. Apr 28, 2013 #3
    Ty what do I do after?
  5. Apr 30, 2013 #4
    i have the initial velocity what do i solve for next? ε, acceleration, Fe, final velocity??? how to find potential difference
    Last edited: Apr 30, 2013
  6. May 2, 2013 #5
    never mind i got it.
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