A woman at an airport is towing her 20.0-kg suitcase at constant speed by pulling on a strap at an angle q above the horizontal (Fig. P5.40). She pulls on the strap with a 35.0-N force, and the friction force on the suitcase is 20.0 N. Draw a free-body diagram of the suitcase.
(a) What angle does the strap make with the horizontal?
(b) What normal force does the ground exert on the suitcase?