To loosen the cap of a peanut butter jar requires a moment about the z axis of 50 in.·lb...

To loosen the cap of a peanut butter jar requires a moment about the z axis of 50 in.·lb. If has the x, y, and ´ direction cosines 6/11, -9/11, and 2/11, respectively, and the forces are a couple, determine the magnitude of needed to loosen the cap.