Acceleration of points on a wheel

[cauchyok]

I don't know why this problem is confusing me so much. Actually I do. I'll explain.A car with wheels of radius R is accelerating at a constant rate. At what point on the tires is there the greatest acceleration, and what is this acceleration?I've attempted this from different perspectives, and it would be useless to describe them all here, so I won't bother.(This is NOT homework.)

 

[Doc Al]

Hint: The acceleration of any point on the wheel with respect to the ground = the acceleration of the point with respect to the center of the wheel + the acceleration of the center of the wheel with respect to the ground.

Add those two vectors to find where their sum is greatest.