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!

Homework Help: Billiard Ball problem

  1. Nov 24, 2009 #1
    Billiard ball rotating and slipping. help

    1. The problem statement, all variables and given/known data
    A ball radius "a" and mass "m" initially spinning counterclockwise with angular speed w=-v0/a with a forward speed vo. The coefficient kinetic friction between the ball and the billiard table is Mu, [Given a,m,vo,mu]
    Determine the work lost to friction while slipping using two methods (they should be equal)
    W=-Ffs where s the distance ball slips not travels
    W= delta Kt + delta Kr

    2. Relevant equations
    Torque= I*alpha

    3. The attempt at a solution

    I found a from equation F= ma where F=-Ff
    Then plug in a to eq V=Vo+at

    I also found alpha from eq Torque= I alpha
    then plug in alpha to eq W=Wo+ alpha t

    set V=RW i got T where the slipping becomes rolling without slipping.

    The questions are
    1. Can i use this t and plug it in to eq X=Xo+Vot+0.5at^2 to find The distance the ball SLIPS??
    2. If i cant use that equation, then How can i find the distance the ball slips?
    3. In finding W= delta Kt + delta Kr, Do I have to use final angular and forward speed that i found from previous calculation or Do i have to find them?

    Thank you for your help.
    Last edited: Nov 24, 2009
  2. jcsd
  3. Nov 24, 2009 #2
    Anybody?? I really need help
  4. Nov 24, 2009 #3
    Please heLP!!!!
  5. Nov 25, 2009 #4
  6. Nov 25, 2009 #5


    User Avatar
    Homework Helper

    Sorry... maybe it's just me but I can't really understand the problem as you've stated it. Is the axis of rotation of the ball supposed to be parallel to the table? (The way you wrote it, it sounds like the ball is spinning around a vertical axis)
  7. Nov 25, 2009 #6
    Its a billiard ball rotating on the table. If you ever played pool before, you know that once you hit the ball its both rotating and slipping then it rolls without slipping
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook