# Maximum radius given rps, static and kinetic friction coefficients

**1. The problem statement, all variables and given/known data**

A computer scientist has dropped a tiny pizza crumb onto a magnetic disk. Later, when it’s turned on, the disk is rotating at 88 revolutions per second about its axis, which is vertical. The coefficients of kinetic and static friction between pizza crumbs and the disk are 1.3 and 1.5 respectively. What is the maximum radius from the axis at which a pizza crumb will stay on the disk?

**2. Relevant equations**

F=ma, a=v^2/r, v=rω

**3. The attempt at a solution**

i really am not sure how to do this question, am i supposed to equate the centripetal force on the crumb with the frictional force? i have converted the rps to rad/s which is 552.93. please help me!

http://ift.tt/1fPqvBd

## Leave a comment