🔍 Key Concepts

• Archimedes' principle – why ships float at all • Meaning of reserve in stability and buoyancy (what is “held in reserve” if the ship is loaded more or damaged) • Relationship between waterline, freeboard, and the ship’s remaining ability to stay afloat

💭 Think About

• Ask yourself: if a ship suddenly takes on water, which spaces must remain empty/air-filled for the vessel to keep floating? Above or below the waterline? • Which option best matches the idea of “extra staying‑afloat capacity” the ship still has after being loaded to its normal draft? • Look at each choice and ask: is this describing volume of hull, difference in water types, or forces? Which one matches the idea of a remaining volume that can still be used to provide flotation?

✅ Before You Answer

• Be clear whether reserve buoyancy refers to volume (space) or forces – do not mix these up • Decide if reserve buoyancy is concerned with spaces above or below the waterline in the intact condition • Eliminate any choice that talks about salt vs. fresh water if the term itself doesn’t clearly involve different water types