On a 'wear indicator type ball Joint, what does it mean when the grease fitting boss is flush with the base? OA. The ball Joint requires lubrication
OB. The ball joint should be replaced
OC. The steering knuckle has loosened from the ball Joint
OD. Nothing, this is how they are when new

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?