2010年1月26日 · Information: "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. Suppose the slope angle is θ = 31.5°, the snow is dry snow with a coefficient of kinetic friction μk = 0.0400, the mass of the skier and equipment is m...

2007年11月25日 · You will have, now, a related rate for the volume of a cone. This is correct to the best of my knowledge, and I note the fact that I took the derivative of the radius, r, because it, too, is not constant (as you can obviously imagine, as it changes depending on how high or low you go in the cone).