A 5.0 g coin is placed 15 cm from the center of the turntable. THe coin has static and kinetic coefficients of friction with the turntable surface of us=.8 and uk=.5. THe turntable very slowly speeds up to 60 rpm. Does the coin slide off?

2 answers

Centrifugal force, Fc
= mrω²
r=0.15m
m=0.005kg
ω=60 rpm
=60*2*π/60s
= 2π s-1

Static frictional force, Fs
= mμs

If Fc>Fs, the coin will slide off, since μs > μk.
answer is actually no