The Keystone Pipeline has D = 36 in. and an oil flow rate Q = 590,000 barrels per day (1 barrel = 42 U.S. gallons). Its pressure drop per unit length, Δp/L, depends on the fluid density rho, viscosity μ, diameter D, and flow rate Q. A water-flow model test, at 20°C, uses a 5-cm-diameter pipe and yields Δp/L ≈ 4000 Pa/m. For dynamic similarity, estimate Δp/L of the pipeline. For the oil take rho = 860 kg/m³ and μ = 0.005 kg/m · s.