Quiz 7A - Week 3

1. The center of gravity (G) is where:

• • The keel structure bends upward

• • Buoyancy force acts vertically

• • Total weight force acts downward

• • Metacenter location is measured

2. The center of buoyancy (B) is defined as:

• • A point at the ship’s freeboard

• • Longitudinal center of the hull

• • Geometric center of submerged hull

• • Center of water pressure on stern

3. When a ship heels, the most affected are:

• • Engine efficiency and temperature

• • Relative positions of G and B

• • Draft forward and trim aft

• • Angle of yaw and surge

4. The vertical distance from keel to G is:

• • Length overall in meters

• • Known as KG in calculations

• • Calculated by using GZ curve

• • Named freeboard by SOLAS

5. Buoyancy always acts in which direction?

• • Diagonally across amidships

• • Vertically upward from B

• • In the same direction as list

• • Perpendicularly to the hull

6. If a weight is loaded on deck, G:

• • Stays at original location

• • Moves to port side quickly

• • Moves upward toward the weight

• • Drops with hydrostatic pressure

7. When cargo is discharged from deck:

• • Buoyancy decreases slightly

• • G moves downward vertically

• • KG increases and GM decreases

• • KM becomes less than KB

8. Displacement of the ship is:

• • Total height above keel

• • Total weight of ship and cargo

• • Net tonnage of deck area

• • KG plus KM in length

9. Loading a heavy cargo below deck:

• • Reduces the area of waterplane

• • Improves GM and lowers KG

• • Always decreases the buoyancy

• • Moves B to port side line

10. When weights shift upward:

• • KM increases by 0.1 m

• • G increases and GM decreases

• • GM increases due to mass

• • G remains constant amidships