Acar's engine consumes 110 kw of power from its fuel, converts some of that to useful shaft power, and rejects 85 kw of heat. what is the engines efficiency?

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.

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.

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.