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Homework Help: Revolutions problem

  1. Oct 17, 2004 #1
    An electron of mass (m=9.1*10^(-31)kg) orbits a proton at a distance of 5.3*10^(-11)m. The proton pulls on the electron with an electric force of 9.2*10^(-8)N.
    How many revolutions per second does the electron make?

    This is what I did:

    m=9.1*10^(-31)kg
    v=5.3*10^(-11)m
    T=9.2*10^(-8)N

    V=sqrt(rT/m)= 23147876.27 m/s

    angular velocity (w) = (v/r) = 4.38^(16) rad/s
    w*(1 rev/(2(pi)rad)) = 9.17*10^9 rev/s

    I was told the answer was wrong.
    Please help
     
  2. jcsd
  3. Oct 20, 2004 #2
    The electrostatic force serves as the centripetal force. It is given by F = mrw^2. Once w has been determined, w/(2 pi) will be the frequency.

    Best regards,
    Kenneth
     
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