centripetal acceleration= friction

m*w^2 r = mu*mg
changing 50 rpm to rad/sec
mu=w^2 r/g=(50*2PI/60)^2 * .12
which is not your answer.

Check my thinking.

ok I thought centripetal force was equal to

m ac

were ac is the centripetal acceleration

which is equal to v^2 divided by r I don\'t recall it being equal to times r

1 answer

V^2/r = r w^2, since w = V/r.