Chapter 4

Question 1

What is matter that has no definite shape and can flow; liquid or gas?

Answer 1

fluids

Question 2

What is the study of motion and forces in fluids

Answer 2

fluid mechanics

Question 3

What is a theory stating that all molecules of a substance are in constant motion and move more rapidly as the objec is heated?

Answer 3

kinetic theory of matter

Question 4

What is the state of matter that has a constant volume but can flow and change its shape?

Answer 4

liquid

Question 5

What is the state of matter where molecules move around so quickly that they are practically unaffected by cohesion and that can vary its volume by contracting and expanding?

Answer 5

gas

Question 6

What is the attraction between atoms or molecules of the same substance?

Answer 6

cohesion

Question 7

What is the attraction between molecules of different substances?

Answer 7

adhesion

Question 8

What is the tendency of a liquid to pull atoms or molecules near the surface back into the liquid, forming a “skin” or film on the surface?

Answer 8

surface tension

Question 9

What is a curved surface of a liquid formed because of a difference in strength between cohesion of the fluid molecules and their adhesion to their container?

Answer 9

meniscus

Question 10

What is the phenomenon in which liquids in thin tubes rise above or fall beneath their own levels because of adhesion and cohesion?

Answer 10

capillarity

Question 11

What is the force exerted per unit of area?

Answer 11

pressure

Question 12

What is the SI unit of pressure that is equal to one Newton per square meter?

Answer 12

Pascal (Pa)

Question 13

What is the pressure caused by gravity pulling on a substance?

Answer 13

gravitational pressure

Question 14

What is the principle stating that a pressure increase applied to a fluid inside a closed container will be distributed equally throughout the container?

Answer 14

Pascal’s principle

Question 15

Who discovered Pascal’s principle?d

Answer 15

Blaise Pascal

Question 16

What is a device that uses Pascal’s principle to multiply a force by using a small-diameter input piston and a large-diameter output piston connect by a liquis- filled reservoir?

Answer 16

hydraulic press

Question 17

What is the ability of a gas to be easily squeezed and compacted into a smaller container?

Answer 17

compressibility

Question 18

What is the law stating that a gas’s volume and pressure are inversely proportional when temperature is held constant?

Answer 18

Boyle’s Law

Question 19

What is the law stating that the volume and temperature of a gas are directly proportional when pressure is held constant?

Answer 19

Charles’s law

Question 20

What is the law stating that gas temperatures and pressure are directly related when volume is held constant?

Answer 20

Amonton’s law

Question 21

What is the gravitational pressure of air?

Answer 21

atmospheric pressure

Question 22

What is an empty space with no matter?

Answer 22

vacuum

Question 23

What is a device used to measure air pressure?

Answer 23

barometer

Question 24

Who are scientists who study the weather?

Answer 24

meteorologists

Question 25

What is a barometer that uses an airtight metal box with thin, flexible walls to measure pressure?

Answer 25

aneroid barometer

Question 26

What is a device used to measure alititude?

Answer 26

altimeter

Question 27

Who was the Greek mathematician who discovered that fluids exert a buoyant force upon objects within them?

Answer 27

Archimedes

Question 28

What is an upward force exerted by a fluis on a solid object placed in the fluid?

Answer 28

buoyancy

Question 29

What is the principle stating that the buoyant force experienced by an object is exactly equal to the weight of the fluid displaced?

Answer 29

Archimedes' principle

Question 30

What is a device that is used to meausre the specific gravity of liquids?

Answer 30

hydrometer

Question 31

What is a technique that uses Archimedes' principle to determine the specific gravity of a solid denses than water?

Answer 31

hydrostatic weighing

Question 32

What is a vessel that can float on top of the water or mauever beneath the surface by changing its buoyancy?

Answer 32

submarine

Question 33

What is the state in which the weight of a submerged object equals the weight of the fluid displacement?

Answer 33

nuetral buoyancy

Question 34

What is a flexible, gas-filled sac that allows the fish to control its buoynacy?

Answer 34

swim bladder

Question 35

What is a type of small airship used for various applicants not requiring great speed or robustness?

Answer 35

blimp

Question 36

What is fluid friction that tends to slow an object moving through a fluid, including air pressure?

Answer 36

drag

Question 37

What are the four main factors that affect drag?

Answer 37

the shape of an object, the size of an object, the speed of an object, and the fluid's density

Question 38

What is the most important factor affecting drag?

Answer 38

the shape of the object

Question 39

What is the scince of shaping objects to allow the smooth flow of fluids around them and reduce drag?

Answer 39

streamlining

Question 40

What limits the height that airships can attain?

Answer 40

the thinning of the atmosphere

Question 41

Why doesn't a ship sink?

Answer 41

it is not made of solid steel; it has components filled with air

Question 42

What is the force on an object that is generated by relative motion between that objects and a fluid and is perpendicular to the direction of fluid flow?

Answer 42

lift

Question 43

What is a structure designed to produce left as it moved relative to a fluid?

Answer 43

foil

Question 44

What type of foil is designed to work in air?

Answer 44

airfoil

Question 45

What type of foil is designed to work in water?

Answer 45

hydrofoil

Question 46

What are the factors that affect lift?

Answer 46

aspect ratio, size of the foil, angle of attack, and velocity and fluid properties

Question 47

What is the angle of a foil that is relative to fluid flow?

Answer 47

angle of attack

Question 48

What is the angle at which maximum lift is achieved?

Answer 48

critical angle of attack

Question 49

What is the phenomenon in which a spinning cylinder or ball causes lift?

Answer 49

Magus effect

Question 50

What is a decrease in lateral pressure exerted by a moving fluid as the fluid's speed increases?

Answer 50

Bernoulli effect