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Homework Help: Escape velocity equations

  1. May 27, 2008 #1
    Determine the escape speed from (a) Jupiter’s moon Callisto with a mass of 1.07 × 10^23 kg and radius 2.4 Mm and (b) a neutron star twice the mass of the sun and a radius of 6 km.

    I want to make sure I'm doing this and have the correct equations..

    For part a)
    Okay, so escape speed is found using the equation
    v=sqrt(2GM/r)
    G=6.67 x 10^-11
    M=1.07 × 10^23
    r=2.4 x 10^6

    v=sqrt(1.427 x 10^13/2.4 x 10^6)
    v=srt(5947416.667)
    v=2438.73 m/s

    For part b)
    v=sqrt(2GM/r)
    G=6.67 x 10^-11
    M=2(1.9891 ×10^30) = 3.9782 x 10^30
    r=6000

    v=sqrt(5.301 x 10^20/6000)
    v=sqrt(8.845 x 10^16)
    v=297403171.9 m/s
     
  2. jcsd
  3. May 28, 2008 #2
    Yep, you have the right formulae, and the right answers too.

    and incase it is mentioned, your neutron star is VERY nearly a black hole too.
     
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