The drag characteristics for a newly designed automobile having a maximum characteristic length of \(20 \mathrm{ft}\) are to be determined through a model study. The characteristics at both low speed (approximately \(20 \mathrm{mph}\) ) and high speed ( \(90 \mathrm{mph}\) ) are of interest. For a series of projected model tests, an unpressurized wind tunnel that will accommodate a model with a maximum characteristic length of \(4 \mathrm{ft}\) is to be used. Determine the range of air velocities that would be required for the wind tunnel if Reynolds number similarity is desired. Are the velocities suitable? Explain.