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Homework Help: E-Fields - trajectory

  1. Jan 27, 2010 #1
    1. The problem statement, all variables and given/known data

    Hello, I have a physics exam on friday. My teacher said one of the questions would be on the TRAJECTORY (of an electron) IN AN E-FIELD. he told us to remember than tanß = sinß / cosß

    we haven't used tan, sin or cos during class work. I was hoping someone could give me a clue to what he means.

  2. jcsd
  3. Jan 27, 2010 #2
    he means that you will need to use tan(beta)
  4. Jan 27, 2010 #3
    yes i know he will give us some form of equation or something to do with tanß
    but how is this related to the trajectory in an e field?
  5. Jan 27, 2010 #4
    say a uniform electric field points in the x direction. but the electron enters the E field at a certain speed 30 degrees above the direction of the E field, then you are going to have initial components of velocities that involve sine and cosine
  6. Jan 28, 2010 #5
    So would the equations be:

    v = ucosß + at
    v^2 = (ucosß)^2 + 2as
    s = (ucosß x t ) + .5at^2
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