1. The problem statement, all variables and given/known data What is the minimum coefficient of static friction necessary to allow a penny to rotate without sliding off a 33.5rpm record (diameter of these old-fashioned records is 0.3), when the penny is placed at the edge of the record. Ignore the size of the penny. 3. The attempt at a solution I know the equation to determine the static friction coefficient. However, I am clueless as to how to proceed from here.