F=MA
M*A=(coefficient of friction - I'll say u)*M*G
The M's cancel out, so you are left with A=uG
Soooo....A=(.6)(9.8)
A=5.88m/s^2
From this you can determine
A=v^2/r, which is the formula for centripetal acceleration.
5.88=v^2/30.5
30.5*5.88=v^2
179.34=v^2
v=13.39 m/s