What coefficient of friction keeps the object from moving?

[ExtendedG]

Homework Statement

So basically this is a two part question, first part was find acceleration of the system (which i already found) with a coefficient of friction of 0.1. B) asks you what coefficient you need for the object not to move?

Homework Equations

The Attempt at a Solution

So I figured the acceleration has to be 0 for the object not to move, and I played around and stuff but nothing really got me the answer I needed. I understand that the force of friction must equal the force applied without friction.. I think :/

 

[azizlwl]

We do not know the whole question.