In the study of aerodynamic drag on a stationary body, an appropriate non-dimensional grouping has been found to be
where, P is the power lost, ρ is the density of the fluid, A is a typical area, and U is the velocity of the fluid. In laboratory tests with a 1:10 scale model at 25ºC, the power lost was measured as 5 W when the air velocity was 0.5 m/s. The power lost in the prototype (kW) at 25ºC when the air velocity is 2 m/s will be most nearly