A student is to design an experiment involving dragging a sphere through a tank of fluid to illustrate

(a) "creeping flow" \(\left(R e_{D}<1\right)\) 

(b) flow for which the boundary layer becomes turbulent \(\left(R e_{D} \approx 2.5 \times 10^{5}\right)\). The student proposes to use a smooth sphere of diameter \(1 \mathrm{~cm}\) in SAE 10 oil at room temperature. Is this realistic for both cases? If either case is unrealistic, select an alternative reasonable sphere diameter and common fluid for that case.