One way to reduce the drag of a blunt object is to install vanes to suppress the amount of separation. Such a procedure was used on model trucks in a wind tunnel study. For tests on a van-type truck without vanes the CD was 0.78. However, when vanes were installed around the top and side leading edges of the truck body (see the figure), a 25% reduction in CD was achieved. For a truck with a projected area of 8.36 m², what reduction in drag force will be effected by installation of the vanes when the truck travels at 100 km/h? Assume standard atmospheric pressure and a temperature of 20°C.

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Vanes