Spark-ignition engine has a compression ratio of 8, an isentropic compression efficiency of 85%, and an isentropic expansion efficiency of 95%. At the beginning of the compression, the air in the cylinder is at 0.1 MPa and 300 K. The maximum gas temperature is found to be 1500 K by measurement. Determine (1) the heat supplied per unit mass, (2) the thermal efficiency, and (3) the mean effective pressure of this engine when modeled with the Otto cycle. Use constant specific heats at room temperature. (Hint: How would