2.2 Consider a piston cylinder arrangement of a general aviation engine. Combustion takes place when the piston is at the top of the cylinder. The volume of the gas stays constant during combustion. If the gas density and temperature are 12.0 kg/m3 and 630 K just before combustion, and the temperature is 4200 K just after the combustion process, determine the gas pressure at the end of the constant-volume combustion. Assume the gas constant for the fuel-air ration is the same for pure air. 2.3 For the conditions of problem 2.2, determine the force exerted on the top of the piston by the gas just before combustion and just after combustion. The piston diameter is 10cm