When the switching means disconnect {HEAD ~ the motor} from {TAIL ~ the electrical power source}, the disks coast to a stop 
When the switching means disconnect { HEAD ~ the motor } from { TAIL ~ the electrical power source } , the disks coast to a stop
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH