Find the velocity given coefficient of friction and radius?

[Kataryx]

Homework Statement

An disk has a radius of 0.2 meters. A lump of putty with a coefficient of static friction of 0.9 is stuck on the edge of the disk.

Let's say the disk starts at rest and gradually speeds up. At what speed will the putty just barely be able to stay in place on the edge of the disk?

Homework Equations

ac=v^2/r
at=(v-vi)/t
Fs=M*N

The Attempt at a Solution

I'm a bit stuck as to where I should start with this.[/B]

 

[gneill]

Hi Kataryx,
Welcome to Physics Forums!

You need to show some work before help can be offered. Did you draw a free body diagram for the putty? What forces are acting?