🔍 Key Concepts

• How a diesel engine works during the power stroke • What actually pushes the piston down after fuel is injected and ignited • Difference between force on the piston and the parts that transmit motion (like the crankshaft and connecting rod)

💭 Think About

• When fuel burns in a closed cylinder, what changes inside the cylinder that can create a force on the piston? • Which choice describes the immediate cause of piston motion, and which choices describe supporting systems or ideas, not the direct cause? • Think about what is physically in contact with the top of the piston during combustion.

✅ Before You Answer

• Identify which option refers to pressure inside the cylinder rather than just fuel/air entering • Separate the direct physical cause (what actually pushes) from the mechanical linkage (what carries the motion away) • Eliminate any answer that talks about a general "concept" without describing a real physical force acting on the piston