1. Limited time only! Sign up for a free 30min personal 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 concept question

  1. Mar 13, 2012 #1
    1. The problem statement, all variables and given/known data
    A piece of fruit falls straight down. As it falls,

    A. the gravitational force does positive work on it and the
    gravitational potential energy increases.
    B. the gravitational force does positive work on it and the
    gravitational potential energy decreases.
    C. the gravitational force does negative work on it and the
    gravitational potential energy increases.
    D. the gravitational force does negative work on it and the
    gravitational potential energy decreases.

    The correct answer is B


    2. Relevant equations



    3. The attempt at a solution

    I want to make sure my reasoning is correct. The answer would be B because when the piece of fruit falls the only force acting upon it is gravity. So relating this to the gravitational potential energy equation Ugrav= Mgy; as the fruit falls its displacement is decreasing due to it getting closer and closer to zero thus making the over all gravitational potential energy decrease.

    Thank you
     
  2. jcsd
  3. Mar 13, 2012 #2
    That's right. And the work done by gravitational force is positive, because the fruit is moved in the same direction as the force is pointed to.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Gravitational potential energy concept question
Loading...