Bennett Mechanical Test Fluid Mechanics and Hydraulics 4

Question 1

An object floats in water when its weight is:

Accepted Answer

Equal to the buoyant force

Answer

Greater than the buoyant force

Answer

Zero

Answer

Greater than its volume

Question 2

Archimedes' principle states the buoyant force on a submerged object equals the weight of the:

Accepted Answer

Fluid displaced by the object

Answer

Object itself

Answer

Container holding the fluid

Answer

Air above the fluid

Question 3

Why does a steel ship float even though steel is denser than water?

Accepted Answer

The hull shape displaces enough water to equal the ship's weight

Answer

Steel becomes lighter in water

Answer

Water pushes harder on metal

Answer

The ship contains helium

Question 4

Two balls of equal size are submerged: one is solid steel, one is hollow plastic. The buoyant force on them is:

Accepted Answer

The same on both

Answer

Greater on the steel ball

Answer

Greater on the plastic ball

Answer

Zero on the plastic ball

Question 5

An object will sink in a fluid if its average density is:

Accepted Answer

Greater than the fluid's density

Answer

Less than the fluid's density

Answer

Equal to the fluid's density

Answer

Equal to its weight

Question 6

A submarine descends by:

Accepted Answer

Increasing its overall density by filling ballast tanks with water

Answer

Becoming lighter

Answer

Heating the surrounding water

Answer

Increasing its volume

Question 7

An object weighs 50 lb in air but only 30 lb when submerged in water. The buoyant force on it is:

Accepted Answer

20 lb

Answer

30 lb

Answer

50 lb

Answer

80 lb