The AQA A-level Physics Paper 3B (June 2023), Option C (Engineering Physics), addresses rotational dynamics, thermodynamics, and engine performance. Topics include moments of inertia, flywheel efficiency, torque analysis, and adiabatic processes in hydraulic brake systems. The paper evaluates angular velocity variations, engine cycle efficiency, and power output of motors. Practical applications in diesel engine operations, braking mechanisms, and heat engine efficiency are explored with quantitative analysis. Keywords: AQA Physics, engineering physics, rotational dynamics, moment of inertia, torque, diesel engine, adiabatic compression, heat engine efficiency.