# Billiard Ball problem

#### aldee11

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
F=ma
Torque= I*alpha
W=v/r
V=vo+at
W=Wo+alpha*t

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:
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#### aldee11

Anybody?? I really need help

Please heLP!!!!

nobody?

#### diazona

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)

#### aldee11

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)
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

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