20.39 Engine oil with properties given below flows at a rate of 136 kg per hour through a 7.5-cm-ID pipe whose inside surface is maintained at 100 C. If the oil enters at 160 C, what will its temperature be at the exit of a 15-m-long pipe? . Pr T, K p, kg/m³ Cp, J/kg K k, W/m k v, m²/s × 103 x 373 842 2,219 0.137 0.0203 276 393 831 2,306 0.135 0.0124 175 413 817 2,394 0.133 0.0080 116 433 808 2,482 0.132 0.0056 84