Steady-state creep rate data are given here for some alloy taken at 200°C (473 K): (h-1) (MPa) 2.7 × 10-3 54 2.3 × 10-2 69 If it is known that the activation energy for creep is 130000 J/mol, compute the steady-state creep rate at a temperature of 230°C (503 K) and a stress level of 50 MPa.

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]