1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Ratio of max height of a projectile to planet radius

  1. Jan 12, 2009 #1
    1. The problem statement, all variables and given/known data

    Hint:Disregard any dissipative effects of the atmosphere of the planet.
    A projectile is launched from the surface of a planet (mass M, radius R)
    with a launch speed equal to 60 percent of the escape speed for that planet.
    The projectile will rise to a maximum height and fall back to the surface of
    the planet.

    What will be the ratio of its maximum height above the surface to the radius of the
    planet, h/R?

    2. Relevant equations

    escape speed:
    KE = E(gravity)
    1/2 mv^2 = (GMm)/R
    F/m = a
    a(gravity) = GM/R^2

    3. The attempt at a solution

    1/2 mv^2 = (GMm)/R
    v(escape) = (2GMm)/R
    v=sqrt((2GM)/R)
    vi = 0.6 sqrt((2GM)/R)

    vf^2 = vi^2 - 2gh
    0 = 0.72GM/R - 2(GM/R^2)h
    2(GM/R^2)h = 0.72GM/R
    h/R = 0.36
     
  2. jcsd
  3. Jan 12, 2009 #2
    Sorry I reworked this problem by myself and I solved it!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Ratio of max height of a projectile to planet radius
Loading...