Phil's Pizza Parlor decides to place a thin, rectangular, plastic sign on top of its delivery van as shown in Fig. P9.73. The sign measures \(2 \mathrm{ft}\) by \(5 \mathrm{ft}\).

(a) Estimate the extra power required to drive the van in standard still air at \(35 \mathrm{mph}\) if the sign faces forward rather than sideways.

(b) The supports for the sign consist of two steel pipes \(10 \mathrm{in}\). long and of \(1 \frac{5}{16} \mathrm{in}\). outside diameter. Estimate the power required to overcome air drag on these two supports with the sign facing forward.

Figure 9.73

35 mph PHIL'S 5.ft PIZZA 2 ft