In an automobile engine, at the end of the upstroke the piston is at its maximum height in a cylinder of exact dimensions. At this time, a precisely measured mixture of fuel and oxidant ignites to form gaseous products. If the ignition temperature is known, how could you calculate the pressure inside the cylinder just before the piston moves downward? Which gas law does this go with? P1V1=P2V2 U=square root:(3RT/m) (T1/V1)=(T2/V2) Others (P1/T1)=(P2/V2) And (P1/T1)=(P2/T2) is wrong.