🔍 Key Concepts
• Metacenter (M) vs center of gravity (G) and what GM (metacentric height) represents
• The difference between stable, neutral, and unstable equilibrium in ship stability
• How the sign of GM (positive, zero, or negative) relates to the ship’s ability to return upright after a small heel
💭 Think About
• Think about what happens to a ship after a small heel when the metacenter is above the center of gravity: does it tend to come back upright, stay where it is, or continue to roll over?
• How is the metacentric height GM defined, and what does it mean if GM is greater than zero, equal to zero, or less than zero?
• Connect the words stable, neutral, and unstable with the sign (plus, zero, minus) of GM.
✅ Before You Answer
• Confirm that GM = KM − KG and what it means physically when M is above G
• Match stable/neutral/unstable with GM > 0, GM = 0, GM < 0 before choosing an answer
• Verify which choice word is used in stability textbooks to describe a vessel with M above G and a righting arm that tends to restore the ship upright for small angles of heel