Physics: Principles with Applications (7th Edition)

a. Calculate the Reynolds number. $$R=\frac{2(0.35m/s)(0.008 m)(1.05 \times 10^3 kg/m^3)}{4 \times 10^{-3}Pa \cdot s}=1470$$ This is less than about 2000, the onset of turbulence. b. If the speed doubles, so will the Reynolds number, so the flow is turbulent.