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therest
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Homework Statement
this question is from 1980.
1980M3. A billiard ball has mass M, radius R, and moment of inertia about the center of mass I=2MR2/5.
The ball is struck by a cue stick along a horizontal line through the ball's center of mass so that the ball initially slides with velocity v0 as shown above. (There's an accompanying diagram. It just shows a cue stick hitting a ball with radius R, not much to see there.) As the ball moves across the rough billiard table (coefficient of sliding friction μk), its motion gradually changes from pure translation through rolling with slipping to rolling without slipping.
a. Develop an expression for the linear velocity v of the center of the ball as a function of time while it is rolling with slipping.
b. Develop an expression for the angular velocity ω of the ball as a function of time while it is rolling with slipping.
c. Determine the time at which the ball begins to roll without slipping.
d. When the ball is struck it acquires an angular momentum about the fixed point P on the surface of the table. During the subsequent motion the angular momentum about point P remains constant despite the frictional force. Explain why this is so.
Homework Equations
vcm=ωr while rolling.
μk*FN=Ffriction
I don't know, all those torque and angular momentum equations?
Τ=Iα, etc.
The Attempt at a Solution
No idea where to start conceptually on this one. Why isn't it just rolling from the atart? Why would friction help it to start rolling? Could comeone just help me to get started, and then maybe I could figure it out from there?