Asked by Anonymous

A coin is placed 11.0 cm from the axis of a rotating turntable of variable speed. When the speed of the turntable is slowly increased, the coin remains fixed on the turntable until a rate of 31 rpm is reached, at which point the coin slides off. What is the coefficient of static friction between the coin and the turntable?
Answered by bobpursley
forcefriction=mg*mu
centripetalforce= mw^2r
w= 31*2PI/60 in rad/sec
set them equal, solve for mu.
Answered by Anonymous
wouldnt w be 2pir/period in s