consider a rotating cylinder with a man in it standing against the wall. The floor is removed.I have to find the minimum velocity for which the man will continue to stay that way(not fall). My question is why do we have to take the max/limiting value of friction?

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anonymous · Answer

|dw:1341053885107:dw|  v is the velocity r is the radius now and  $$\mu  $$ is the cofficient of friction now $$v ^{2}/r$$ will be the acc and the force willl be $$\mu m v ^{2}/r$$ here mv^2/r is due to the cylinder so has to be adjusted to the max so that it counteracts mg so friction will be max