Circular Motion

A motor cyclist wants to drive in horizontal circles on the vertical inner surface of a large cylindrical wooden well of radius \(8.0 \mathrm{~m}\), with minimum speed of \(5 \sqrt{5} \mathrm{~ms}^{-1}\). The minimum value of coefficient of friction between the tyres and the wall of the well must be \(\left(g=10 \mathrm{~ms}^{-2}\right)\)