08.48: A block of mass M on a horizontal surface is connected to the
a.22z co3zyz u end of a massless spring o
czyo2uzz 23a .f spring constant k. The block is pulled a distance x from equilibrium and when released from rest, the block moves toward equilibrium. What minimum coefficient of kinetic friction between the surface and the block would prevent the block from returning to equilibrium with non-zero speed?