The fatigue data for a brass alloy are given as follows: stress amplitude (mpa) cycles to failure 170 3.7 × 104 148 1.0 × 105 130 3.0 × 105 114 1.0 × 106 92 1.0 × 107 80 1.0 × 108 74 1.0 × 109 (a) make an s–n plot (stress amplitude vs logarithm of cycles to failure) using these data. (b) determine the fatigue strength at 4 × 106 cycles. (c) determine the fatigue life for 120 mpa.

Carbon dioxide gas expands isotherm a turbine from 1 mpa, 500 k at 200 kpa. assuming the ideal gas model and neglecting the kinetic and potential energies, determine the change in entropy, heat transfer and work for each kilogram of co2.

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]

10 kg of co2 is initially contained at 400 kpa and 300 k. the gas constant for carbon dioxide is 189 j/lkg k) and has a specific heat ratio, k, of 1.289. isentropic expansion then occurs until the pressure is 200 kpa. a) determine the initial volume of co2 in m. b) determine the final temperature in k. c) determine the work done by the system during the expansion kl.