A warehouse worker must push a hand cart loaded with cases of textbooks. The total weight of the cart and textbooks is 480 lbs. If the worker weighs 180 lbs. and a horizontal force of 80 lbs must be exerted to initially set the cart in motion.

1. (2 points) What is the minimum required coefficient of friction between his shoes and the floor? You may assume that the cart is equipped with frictionless wheels.

1. (2 points) Assume that the same job is performed by a 130 lb. female. Would the required COF increase, decrease, or stay the same?