For a steel alloy it has been determined that a carburizing heat treatment of 11.9 h duration will raise the carbon concentration to 0.39 wt% at a point 2.1 mm from the surface. Estimate the time necessary to achieve the same concentration at a 6.2 mm position for an identical steel and at the same carburizing temperature.

An ideal otto cycle with air as the working fluid has a compression ratio of 8. the minimum and maximum temperatures in the cycle are 300 k and 1340 k. use constant specific heats at room temperature to determine (a) the amount of heat transferred to the air during the heat- addition kj/kg, (b) the thermal efficiency, and (c) the thermal efficiency of a carnot cycle ope limits. process, in rating between the same temperature