The skateboarder in the figure is coasting down a ramp, and there are three forces acting on her: her weight (magnitude = 675 N), a frictional force (magnitude = 125 N) that opposes her motion and a normal force N (magnitude = 612 N) Concepts: Part b of the figure shows each force, along with the displacement of the skateboarder. By examining these diagrams and without doing any numerical calculations, determine whether the work done by each force is positive, negative, or zero. Provide a reason for each answer. Calculations: Determine the net work done by the three forces when she coasts for a distance of 9.2 m.

Transcribed Image Text:

θ 65.0°. Weight component 25.0 180.00 0-90.0