Discussion and hints:

For this problem, you should write down the velocity and acceleration rigid body kinematics equations relating the center of the disk O to point A:

v_A = v_O + ω x r_A/O

a_A = a_O + α x r_A/O - ω²r_A/O

All of the variables on the right hand side of these equations have known values.

Carefully study the velocity (BLUE) and acceleration (RED) information for points O and A on the disk as it moves along the horizontal axis. Can you see the contributions of the various terms in these kinematics equations for velocity and acceleration?

QUESTION: Can you identify from the animation the positions at which point A is increasing in speed? Or, when the point is decreasing in speed?  Do these positions of increasing/decreasing speed make sense to you?

 

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Any questions??