For the same column develop a performance index which can be used to select a material to avoid failure which would minimise cost. show on the appropriate materials selection chart the selection line that would be used to select a material and based on this, suggest a few appropriate materials.

Calculate the bore of a cylinder that has a stroke of 18 inches and an extension time of 6 seconds at a flow rate of 4 gal/min.

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]

What is the heat treatment of metals? what is the benefit of it? why and how it's useful? answer in details, do not write by hand.