14 12 A block of mass m rests on a rough incline plane. Which of the following is the correct free-body diagram for this situation? KO mg 12\fTo maintain a constant speed, the force provided by a car's engine must equal the drag force plus the force of friction of the road (the rolling resistance). The density of air is 1.2 kg/m. (a) What are the drag forces in newtons at 78 km/h and 106 km/h for a Toyota Camry? (Drag area = 0.70 m? and drag coefficient = 0.28.) at 78 km/h Z at 106 km/h N (b) What are the drag forces in newtons at 78 km/h and at 106 km/h for a Hummer H2? (Drag area = 2.44 mand drag coefficient = 0.57.) at 78 km/h N at 106 km/h N Supporting Materials