A small button placed on a horizontal rotating platform with diameter 0.324m will revolve with the platform when it is brought up to a rotational speed of 42.0rev/min , provided the button is a distance no more than 0.142m from the axis. Part A What is the coefficient of static friction between the button and the platform? Part B How far from the axis can the button be placed, without slipping, if the platform rotates at 60.0rev/m ?