The drawing shows an extreme skier at three locations on a ski run a) a straight section,b)a circular section and c)an airborn phase in which the skier is in free fall .At the right of the drawing are four possible directions for the net force that acts on the skier. What is the direction of the net force of the net force at a,b,c?assume there is no friction or air resistance at any point along the ski run.

Question

Choice 1.)2,1,1. 1
Choice2.)4,3,2. 4 I
Choice.3)3,1,3. I. 2.(connectline from 4 to 2)
Choice4.)2,3,2. I
Choice5.)2,1,3. 3

Answer 1

No friction?
straight section. Net force is zero (gravity is negated by upward supporting force)
curved section. Net force is down on the both sides: on the incoming side, speed is increasing down the ramp, and on the up side, speed is decreasing.
in the air: net force is downward, the skier is accelerating downward.