I need help understanding the problem. Thanks

You have an internship working at a company that designs and produces washing and drying equipment. Your supervisor is in the process of designing a new, very large dryer to be used in commercial establishments with intense laundry needs, such as restaurants (tablecloths, napkins) and hotels (sheets, towels). In a dryer, a cylindrical tub containing wet material is rotated steadily about a horizontal axis as shown in the figure below.