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Homework Help: Speed of Alpha Particle

  1. Mar 29, 2005 #1
    An alpha particle is accelerated to a velocity v in a particle accelerator by a potential difference of 1200 V. Which of the following potential differences would be needed to give the alpha particle twice the velocity?

    A. 7200 V
    B. 4800 V
    C. 4100 V
    D. 2400 V
    E. 1700 V

    At first, I thought of a ratio. That means doubling the speed would double the voltage. But, the answer that I thought of, 2400 V, seems too obvious... Is there any certain equation I can use to be certain of my answer? All help is appreciated.
  2. jcsd
  3. Mar 29, 2005 #2


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    Nope.4 times more...Do you see why?HINT:Think where does the KE of the particle (nonrelativistic,for simplicity) comes from...:wink:

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