Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Moon Gravitational Force Problem

  1. Sep 30, 2008 #1
    1. In tests on earth a lunar surface exploration vehicle (mass = 5.68 × 103 kg) achieves a forward acceleration of 0.220 m/s2. To achieve this same acceleration on the moon, the vehicle's engines must produce a drive force of 1.42 × 103 N. What is the magnitude of the frictional force that acts on the vehicle on the moon?
    G= 6.673*10-11
    mEarth= 5.98*1024
    mMoon= 7.35*1022
    rEarth= 6.38*106
    rMoon= 1.74*106

    2. F=Gm1m2/r2


    3. All I know is that the mass is the same on earth as it is on the moon. I figured that the frictional force is the opposite of the driving force. I am lost. Please help.
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Sep 30, 2008 #2

    Hootenanny

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member


    I'll give you a hint: this question has nothing to do with Newton's law of gravitation, but everything to do with Newton's Second Law :wink:
     
  4. Sep 30, 2008 #3
    So do I use F-fk=ma?
     
  5. Sep 30, 2008 #4

    Hootenanny

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Sounds good to me :approve:
     
  6. Sep 30, 2008 #5
    Got it thanks!
     
  7. Sep 30, 2008 #6

    Hootenanny

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    A pleasure.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook