🔍 Key Concepts

• Horsepower types in marine engines and where they are measured (inside cylinder vs at crankshaft vs at propeller) • Difference between indicated horsepower and the power actually delivered for use • Effect of mechanical losses and friction between the cylinder and the output shaft

💭 Think About

• Which term describes power that has already had internal engine losses (like friction in pistons, bearings, etc.) taken out, and is measured at the crankshaft? • Which option refers to power calculated from cylinder pressures, not directly measured at the output shaft? • Think about what word you would use when putting an engine on a dynamometer (test stand) to see how much useful power it can actually deliver.

✅ Before You Answer

• Match the definition: "power at the end of the crankshaft available for doing work" with the correct term • Eliminate the choice that refers to power inside the cylinders before friction and mechanical losses • Be careful not to confuse friction horsepower (power lost to friction) with the power that is actually available for use