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!

Gravitationl Potential energy

  1. Feb 28, 2009 #1
    1. The problem statement, all variables and given/known data
    A 2.35 kg ball is attached to a ceiling by a
    1.92 m long string. The height of the room is
    5.92 m .
    The acceleration of gravity is 9.8 m/s2 .
    What is the gravitational potential energy
    associated with the ball relative to the ceiling?
    Answer in units of J

    What is its gravitational potential energy rel-
    ative to the floor? Answer in units of J.

    What is its gravitational potential energy rel-
    ative to a point at the same elevation as the
    ball? Answer in units of J.

    2. Relevant equations
    PE=mgh

    3. The attempt at a solution
    I TRIED TO USE THE EQUATION BUT WHEN I PUT IT IN IT WAS WRONG MAYBE I AM CALCULATING WRONG PLEASE HELP MAYBE IF U CAN PROVIDE A MODIFIED EQUATION OR EVEN A SIMPLE ONE THAT WOULD HELP A LOT!
     
  2. jcsd
  3. Feb 28, 2009 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Perhaps if you thought of the equation as PE = mgy, where y is the vertical position with respect to your reference point, you may understand it better.

    For example, if you choose the ceiling as your reference, that means that y = 0 at the ceiling. What's the y value of the ball in that case?
     
  4. Feb 28, 2009 #3

    Doc Al

    User Avatar

    Staff: Mentor

    Hint: Pay attention to the sign of your answer.
     
  5. Feb 28, 2009 #4
    thanks a lot it helped a lot especially the last part, it worked.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Gravitationl Potential energy
  1. Potential energy (Replies: 1)

  2. Potential Energy (Replies: 5)

Loading...