Find the Coefficient of Friction Given Frequency

[CoffexCream]

Homework Statement

A rubber Eraser is placed on a cardboard record on a turntable. The turntable is set to 33 1/3 rotations per minute. what is the max radius for the eraser to be placed without slipping. but first calculate the coefficient of friction. You will not be given mass or radius of the 'record'

Homework Equations

a_c=V²/r
a_c= 4pi²rf²
u^s=Tan $$\theta$$

The Attempt at a Solution

no idea as to how to get this...i can't seem to make any connections...

$$\mu$$Fn=m x a_c
$$\mu$$=Tan $$\theta$$
Tan $$\theta$$=m x a_c
Tan $$\theta$$= a_c / g
Tan $$\theta$$= 4$$\pi$$^2rf^2
then acceleration can be either of the centripetal acceleration equations but the n i get totally stuck because i can't get rid of r xD

 

[BishopUser]

perhaps the fact that it is a rubber eraser and a cardboard turntable means something. i would check your textbook for useful tables

 

[CoffexCream]

unfortunately this question was randomly made by my teacher and its not in the textbook >.>