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!

Gravitational Potential Energy Problem

  1. Apr 19, 2016 #1
    1. The problem statement, all variables and given/known data

    2. Relevant equations
    ΔPE = G × M₁ × M₂ (1/Ri - 1/Rf)
    G = gravitational constant
    M₁ = mass of one object
    M₂ = mass of the other object
    Ri = initial distance
    Rf = final distance
    ΔPE = -ΔKE
    3. The attempt at a solution
    My solution is v = 2√(GM/d). I am making sure it is correct.
  2. jcsd
  3. Apr 19, 2016 #2


    User Avatar
    Homework Helper
    Gold Member

    I believe your answer is correct. But we can't tell if your steps are correct unless you show your work.
  4. Apr 19, 2016 #3
    ΔPE = G × M₁ × M₂ (1/Ri - 1/Rf)
    ΔPE 5M= G × 5M × m (1/2d - 1/d) = -5GMm/2d
    ΔPE M= G × M × m (1/d - 1/2d) = GMm/2d
    ΔPE total = ΔPE 5M + ΔPE M = -2GMm/d

    ΔPE = -ΔKE = 2GMm/d
    (1/2)mv2 = 2GMm/d
    v = 2√(GM/d)
  5. Apr 19, 2016 #4


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Looks good.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Discussions: Gravitational Potential Energy Problem