Chapter 6, Problem 40P

In downhill speed skiing a skier is retarded by both the air drag force on the body and the kinetic frictional force on the skis. (a) Suppose the slope angle is θ = 40.0°, the snow is dry snow with a coefficient of kinetic friction µ_k = 0.0400, the mass of the skier and equipment is m = 85.0 kg, the cross-sectional area of the (tucked) skier is A = 1.30 m², the drag coefficient is C = 0.150, and the air density is 1.20 kg/m³, (a) What is the terminal speed? (b) If a skier can vary C by a slight amount dC by adjusting, say, the hand positions, what is the corresponding variation in the terminal speed?