5. When the relation between the controlling force (Fc) and radius of rotation (r) for a spring controlled governor is Fc = ar + b, then the governor will be
6. The two links OA and OB are connected by a pin joint at O. If the link OA turns with angular velocity ?1 rad/s in the clockwise direction and the link OB turns with angular velocity ?2 rad/s in the clockwise direction, then the rubbing velocity at the pin joint O is (where r = Radius of the pin at O)