Answer Happy

A car (that looks like it is from the 1980s) has a combined drag*area (Co*A) of 3.25 m2 with no attachments (no sign). The rolling resistance of the vehicle at 55 mph (24.6 m/s) is known to be 667.2 N. 6 ft Eat at Joe's 3 ft = What is the power (Power Force*Veloc) required to drive the vehicle in this "clean" form (no sign attached) at 55 mph? Assume: p = 1.225 kg/m3 and u = 1.78E-5 kg/m.s
Now the same 1980s classic vehicle is used to hold up the sign "Eat at Joe's" as shown in the picture. It is still traveling at 55 mph (24.6 m/s) as before. What is the drag force for the sign only in this new setup? Known: & Co of the sign is 1.19 p = 1.225 kg/m3 and u = 1.78E-5 kg/m.s The area of the sign is 18 ft? or 1.67 m2
Given the calculated drag force of the sign, then the TOTAL power required (vehicle and sign) to move at 55 mph is most closely: