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**Classical Mechanics**Level 4

Long cylinder of radius \(R \) is displaced along its axis with a constant velocity \(v\) inside a stationary cylinder of radius \(r\). The space between the cylinders is filled with viscous liquid .Find the velocity of liquid as a function of the distance \(x\) from the axis of cylinders. Flow of liquid is assumed to be laminar. \(V= vln[ax/r]/ln[bR/r]\). Find \((a+b)^2 \).