15. [2pt] What is the magnitude of B ? 16. [6pt] Power is transmitted from the motor A to a machine tool at F. The diameters of the shafts are DAB =15 mm, DCD =18 mm, DEF =40 mm. The radii of the gears are RB =41 mm, RD =41 mm, RC =142 mm, RE =142 mm.The motor frequency is 25 Hz, and Allowed =74.5 MPa. What is the maximum power of the motor?