Sienna made a chart listing the steps that describe how a four-stroke heat engine operates. A 3 column table with 4 rows. The first column is labeled step with entries 1, 2, 3, 4. The second column is labeled name with entries intake, ignition, compression, exhaust. The last column is labeled description with entries piston moves down and fuel-air mixture enters the cylinder, spark plug fires and causes combustion leading to gas expansion, piston moves up, temperature of gas increases and piston moves up pushing burned gas through exhaust valve. Which best describes Sienna’s error? The descriptions for intake and ignition should be switched with one another. During compression, temperature does not increase, it decreases. Compression happens before ignition, so it should be step 2. The piston moves down, not up, during the exhaust step.
