Parasite drag doubles with velocity and parasite power cubes with velocity......
Thus, the resultant power needed to overcome this drag will vary as the cube of velocity
http://en.wikipedia.org/wiki/Drag_(physics)
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"For high velocities (or more precisely, at high Reynolds number) drag will vary as the square of velocity. Thus, the resultant power needed to overcome this drag will vary as the cube of velocity."
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Drag depends on the properties of the fluid and on the size, shape, and speed of the object. One way to express this is by means of the drag equation:
F_D\, =\, \tfrac12\, \rho\, v^2\, C_D\, A
where
FD is the drag force,ρ is the density of the fluid,[9]v is the speed of the object relative to the fluid,A is the cross-sectional area, andCD is the drag coefficient – a dimensionless number.
The drag coefficient depends on the shape of the object and on the Reynolds number:
R_e=\frac{vD}{\nu}
where D is some characteristic diameter or linear dimension and ν is the kinematic viscosity of the fluid (equal to the viscosity μ divided by the density). At low Reynolds number, the drag coefficient is asymptotically proportional to the inverse of the Reynolds number, which means that the drag is proportional to the speed. At high Reynolds number, the drag coefficient is more or less constant. The graph to the right shows how the drag coefficient varies with Reynolds number for the case of a sphere.
For high velocities (or more precisely, at high Reynolds number) drag will vary as the square of velocity. Thus, the resultant power needed to overcome this drag will vary as the cube of velocity. The standard equation for drag is one half the coefficient of drag multiplied by the fluid mass density, the cross sectional area of the specified item, and the square of the velocity.
Wind resistance is a layman's term for drag. Its use is often vague, and is usually used in a relative sense (e.g. a badminton shuttlecock has more wind resistance than a squash ball).
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