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Homework Help: Centripetal force and acceleration

  1. Jul 27, 2009 #1
    1. The problem statement, all variables and given/known data
    The moon takes 27.3 days to circle Earth and its centre is located 3.84 x 108 m from the centre of Earth. What is the Moon’s acceleration?

    2. Relevant equations
    a=v^2/r, a=4(pi)^2mr/T^2

    3. The attempt at a solution
    i dont know how to answer this question becuase i dont know what im suppossed to do with the 27.3 days.
  2. jcsd
  3. Jul 27, 2009 #2
    Your equations look good except for the "m" in the second equation. Where did that come from?

    Anyways, the units of acceleration is the meter per second per second, m/(s^2). You must convert the days to seconds. This is a common procedure for many intro physics problems.
  4. Jul 27, 2009 #3
    so then i would just use the second equation i provided(excluding the m) plug everything in and get an answer of 2.72 x 10^-3 m/s2??
  5. Jul 27, 2009 #4
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