100 kg/s of a crude oil is heated from 20°C to 40°C through the tube side of a multitube heat exchanger. The crude oil flow is divided evenly among all 100 tubes in the tube bundle. The ID of each tube is 10 mm, and the inside tubewall temperature is maintained at 100°C. Average properties of the crude oil are ρ = 950 kg/m³, c_p = 1.9 kJ/kg∙K, k = 0.25 W/m∙K, μ = 12 mPa∙s, and μ_w = 4 mPa∙s. Estimate the rate of heat transfer and the tube length.