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!

The Energy Method

  1. May 8, 2007 #1
    1. The problem statement, all variables and given/known data
    A solid hemi-sphere of radius r rests on a hard flat surface. If rolled slightly in 1 direction and released, the hemisphere will rock from side to side, assume no slipping. Write an expression for the kinetic energy of the hemi-sphere during the small amplitude motion


    2. Relevant equations

    0.5mv^2

    3. The attempt at a solution

    Not sure even where to start :cry:
     
  2. jcsd
  3. May 9, 2007 #2

    berkeman

    User Avatar

    Staff: Mentor

    Start by figuring out how the center of mass of the hemisphere is raised when it is tilted to some angle theta. That raising of the CM is what provides the energy to make the motion happen.
     
  4. May 10, 2007 #3
    thanks I will give it a go and get back, im assuming that the center of mass would be through the axii of symetry and 3/8th's the radius i.e x0,y0,z3r/8
     
  5. May 11, 2007 #4
    ok i am completely stuck, i have no idea how to work this out
     
  6. May 11, 2007 #5

    berkeman

    User Avatar

    Staff: Mentor

    Can you do it for a traditional pendulum?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?