🔍 Key Concepts

• Purpose of lube oil in a main propulsion engine (what jobs does it perform?) • What happens when oil and water mix inside machinery (think of emulsions) • Effects of contamination on bearing surfaces and film strength

💭 Think About

• Which choice best describes how the lubricating ability of the oil is affected by water, not just a side effect like temperature change? • Think about the thin oil film between moving metal parts: what would water do to that film? • Among the options, which one is most directly related to increased friction, wear, or possible bearing failure?

✅ Before You Answer

• Identify which option directly mentions loss of lubrication quality, not just a related system change. • Ask whether water would make the flash point go up or down, and if that’s even the main concern here. • Consider how an emulsion (oil and water mixed like milk) behaves compared to clean, clear lube oil on metal surfaces.