Physics 161
posted by Jake .
A cat dozes on a stationary merrygoround, at a radius of 6.9 m from the center of the ride. The operator turns on the ride and brings it up to its proper turning rate of one complete rotation every 7.3 s. What is the least coefficient of static friction between the cat and the merrygoround that will allow the cat to stay in place?

centripetal force= friction force
m*w^2 r= mu*mg
w=2PI/period= 2PI/7.3 rad/sec
solve for mu. 
what is your "m" in your equations stand for?

i really wanna know that why is centripetal force equal to frictional force???
n a request...
free body diagram please!!
please...