Compute all parts of given question:
Question: A small button placed on a horizontal rotating platform with diameter 0.330m will revolve with the platform when it is brought up to a rotational speed of 39.0rev/min , provided the button is a distance no more than 0.150m 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 58.0rev/min?
I need help to find the coefficient of static friction between the button and the platform.