The ends of two fixed rods an and b are each made in the form of a single threaded screw of mean radius 6mm and pitch 2mm. rod a has a right handed thread and rod b has a left handed thread. the coefficient of static friction between the rods and the rods and the threaded sleeve is 0.12. determine the magnitude of the couple that must be applied to the sleeve in order to draw the rods closer

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.