Seaworthiness of Ships. Test 7

What happens to cause a vessel to be in a state of 'Unstable Equilibrium?'

When a vessel is rolling very heavily.
When the metacentre and the centre of gravity, are at the same height above the keel.
When a vessel has a very large GM.
When the centre of gravity rises above the metacentre.

What effect does 'Hogging,' have on a vessel's draught?

What is the principle of Archimedes?

That every floating body displaces it's own weight of the liquid in which it floats.
That a floating body must be completely watertight, in order for it to float.
That a floating body becomes unstable, if the density of the water it is floating in exceeds the specific gravity of salt water.
That every body that floats displaces at least twice its own weight in water.

What does the term 'Trim' mean?

The difference between the mean draught and the after draught.
The difference between the draught at the forward perpendicular and the draught at the after perpendicular.
The difference between the mean draught, and the forward draught.
The state of a vessel on even keel.

What is the 'Centre of Buoyancy of a ship?'

The point through which the force of buoyancy, is considered to act downwards.
It is the middle point of the watertight volume, above the waterline.
It is the centre point of each cargo hold, in a fully laden vessel.
The geometrical centre of underwater volume & the point through which the force of buoyancy may be considered to act upwards.

What is an 'Angle of Loll?'

It is the period in which a vessel momentarily rests after heeling one way or the other, before returning to the upright position.
It is simply the angle of each variable roll of a heeled vessel.
It is the angle or list a vessel settles at, after a shift of cargo.
It is the list angle at which a vessel with negative stability comes to rest.

What is the equilibrium state of the vessel in this diagram?

What are the 'effects' of free surface?

It results in a loss of bouyancy.
It causes the ship to 'go by the head', thus increasing the risk due to heavy pitching.
It cause a loss of GM, thereby creating a possibly dangerous situation.
It causes an increase in GM, thereby making the ship roll very heavily.

What does fresh water allowance or 'FWA ' mean?

The amount the laden fresh water draft must be reduced by, to equal the maximum allowed laden salt water draft.
The amount of fresh water that may be consumed by each crew member daily, during rationing.
The amount the vessel may submerge it's maximum salt water draft by, when loading in fresh water.
The maximum amount of fresh water a fully laden vessel is allowed to carry.

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