A 730.0 N man, carrying a 2M kg physics textbook, stands at the center of a frozen pond of radius 8.0 M. He is unable to obtain to the other side because of a lack of friction among his shoes and the ice to overcome his difficulty; he throws his textbook horizontally at a speed of 5M m/s toward the north shore. How long (in s) does it take him to reach the south shore?