Andy, the manager of EZ
Trucking, would like to convince his boss to invest in installing
air deflectors on their 18-wheelers. Research has shown that the drag
coefficient, C_{D}, is lower for an 18-wheeler with an air deflector
(from 0.95 to 0.75). How can he show that the air deflector will
save the company a small fortune?

Questions

What is the drag exerted
on the 18-wheeler with and without the air deflector?

Approach

The drag force is directly proportional to the
fuel consumption.

Base the analysis on a frontal area, A, of 100 ft^{2}.

Assume the 18-wheeler runs at an average speed of 65 mph on the highway.

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