CHAPTER 13: LIQUIDS

Question 1

Force / Area =

Answer 1

Pressure

Question 2

Who was the 17th-century scientist who first discovered that pressure within a fluid is transferred without loss to all parts of the fluid and to the walls of the container?

Answer 2

Blaise Pascal

Question 3

When scientists use the term ‘total pressure’, they are referring to _.

Answer 3

the pressure of the atmosphere and the pressure from the liquid

Question 4

What is required for an object to sink in a fluid?

Answer 4

The object is denser than the fluid in which it is immersed.

Question 5

When a paintbrush is pulled out of water, the hairs on the brush are held together by _.

Answer 5

surface tension

Question 6

Liquids are _.

Answer 6

practically incompressible

Question 7

Which of the following rely on Pascal’s principle to operate?

Answer 7

Pumping Stations, Construction Equipment, Automobile Lifts.

Question 8

A boat floating in salt water will _ when floating in fresh water.

Answer 8

float higher than

Question 9

What is the principle of flotation?

Answer 9

A floating object displaces a weight of fluid equal to its own weight.

Question 10

If your hair is long and you let it hang into the sink or bathtub, water will seep up to your scalp because of _.

Answer 10

capillary action

Question 11

The net force acting on a submerged object is upward because _.

Answer 11

pressure is greater on the bottom of the object due to its depth

Question 12

The deeper you swim down in a lake, the more _ you will feel.

Answer 12

pressure

Question 13

The pressure in a liquid depends on what two things?

Answer 13

The density of the liquid, the depth of the submerged object.

Question 14

A fish swimming in water falls under what buoyancy rule?

Answer 14

The object has a density equal to the density of the fluid in which it is immersed.

Question 15

Where would a swimmer feel more pressure: 10 feet below the surface of a fresh water lake or 10 feet below the surface of a pool?

Answer 15

Neither; the pressure depends only on the depth, not the size, of the body of water.

Question 16

A hydraulic lift in an automobile service station obeys _.

Answer 16

Pascal’s principle

Question 17

The attraction of like material to one another is known as _.

Answer 17

cohesion

Question 18

When a stone is submerged in water, the stone will displace a water equal to the _ of the stone.

Answer 18

volume

Question 19

The attraction of unlike materials to one another is known as _.

Answer 19

adhesion

Question 20

Which of the following is not an example of surface tension?

Answer 20

A boat floating on water.

Question 21

When soup is placed in the refrigerator and cooled, a thin layer of fat rises and floats on top of the cold soup. This is because _.

Answer 21

when the soup cools, the surface tension increases

Question 22

A bucket with three vertical holes one above the other is filled with water. Which statement is true?

Answer 22

Water in the bottom hole will spurt the farthest away from the bucket and the top hole will spurt the least.

Question 23

Who was the 3rd century BC Greed scientist who first discovered a relationship between buoyancy and the displaced liquid?

Answer 23

Archimedes

Question 24

The net upward force of an object submerged in a fluid is known as _.

Answer 24

the buoyant force

Question 25

What is required for an object to float in a fluid?

Answer 25

The object is less dense than the fluid in which it is immersed.

Question 26

How does pressure relate to force?

Answer 26

Pressure is force per unit area.

Question 27

Water pressure on a submerged object is greatest against its _.

Answer 27

bottom

Question 28

Does the buoyant force on a submerged object depend on the volume of the object or on the weight of the object?

Answer 28

Volume.

Question 29

Lobsters live on the bottom of the ocean, which means their density is _.

Answer 29

greater than the density of sea water

Question 30

How much air must a 100-ton blimp displace to float and neither rise nor sink?

Answer 30

100 tons.

Question 31

What happens to the pressure in all parts of a confined fluid if the pressure in one part is increased?

Answer 31

The pressure everywhere increases by the same amount.

Question 32

If an object suspended by a scale shows a weight of 3 N in air, and 2 N when submerged in water, the buoyant force on the submerged object is _.

Answer 32

1 N.

Question 33

Water pressure in a lake is greater _.

Answer 33

at the bottom

Question 34

Distinguish between an immersed and a submerged body.

Answer 34

A submerged body is completely surrounded by fluid, whereas an immersed one is partially or completely surrounded.

Question 35

A completely submerged object always displaces its own _.

Answer 35

volume of fluid

Question 36

The operation of a hydraulic press best illustrates _.

Answer 36

conservation of energy

Question 37

Suppose you increase the height of the object WITHOUT changing its depth under water. What will happen to the force due to pressure on the bottom of the object?

Answer 37

The force due to pressure on the bottom of the object will increase.

Question 38

Suppose you increase the height of the object WITHOUT changing its depth under water. What will happen to the net buoyant force?

Answer 38

The net buoyant force will increase.

Question 39

Suppose you increase the depth of the object WITHOUT changing its height. What will happen to the force due to pressure on the bottom of the object?

Answer 39

The force due to pressure on the bottom of the object will increase.

Question 40

Suppose you increase the depth of the object WITHOUT changing its height. What will happen to the net buoyant force?

Answer 40

The net buoyant force will stay the same.

Question 41

On what factors does the buoyant force acting on an object depend?

Answer 41

Height of the object.

Question 42

When a load of wood is thrown overboard from a boat in a swimming pool, the pool level _.

Answer 42

remains unchanged

Question 43

A stone submerged in water displaces the _.

Answer 43

volume of water

Question 44

The pressure increases on a block resting on a table when you increase the _.

Answer 44

downward force on the block

Question 45

What will these objects do in water: an object denser than water, an object less dense than water, an object that has the same density as water.

Answer 45

Sink, float, neither float nor sink.

Question 46

A block of wood with a piece of iron tied to the top of it floats in a bucket of water. If the wood and iron are turned over so that the iron is submerged beneath the wood, the water level at the side of the bucket _.

Answer 46

remains the same

Question 47

The buoyant force on a floating object is _.

Answer 47

equal to the object's weight

Question 48

How does the buoyant force on a submerged object compare with the weight of the water displaced?

Answer 48

The buoyant force is equal to the weight of the water displaced.

Question 49

Calculate the pressure a 50- N block exerts on the table it rests on if its area of contact is 50 cm2 .

Answer 49

P=1 N/cm^2

Question 50

When an ice cube in a glass of water melts, the water level _.

Answer 50

remains the same

Question 51

An object having the same density as water will _.

Answer 51

neither sink nor float in water

Question 52

How does pressure at the bottom of a body of water relate to the weight of water above each square meter of the bottom surface?

Answer 52

The pressure is the weight of the water divided by 1 m^2.

Question 53

How does the volume of a completely submerged object compare with the volume of water displaced?

Answer 53

The volumes are equal.

Question 54

The concept of pressure involves both _.

Answer 54

force and area

Question 55

If a weighted air-filled balloon sinks in deep water, it will _.

Answer 55

be acted on by a continuously decreasing buoyant force

Question 56

When scrap iron in a boat is thrown overboard in a swimming pool, the pool level _.

Answer 56

falls

Question 57

If you swim beneath the surface in saltwater, will the pressure be greater than in fresh water at the same depth?

Answer 57

The pressure will be greater.