For the following situations of steady flow, determine whether flow is laminar or turbulent: 

(a) Water at 10°C flowing at an average velocity of 2 m/s in a 100-mm pipe;

(b) Air at 2-atm pressure and 180°F flowing at 50 ft/s in a 12-in. duct;

(c) Oil with a specific gravity of 0.78 and a viscosity of 20 cP flowing at 5 ft/s in a 2-in. pipe;

(d) Polymer melt with a density of 900 kg/m³ and a viscosity of 1 Pa-s flowing at 0.2 m/s in a 15-mm tube.