Chapter 4

Question 1

matter that has no definite shape and can flow; liquids and gases

Answer 1

fluids

Question 2

the study of motion and forces in fluids

Answer 2

fluid mechanics

Question 3

states that all molecules of a substance are in constant motion and move more rapidly as the object is heated

Answer 3

kinetic theory of matter

Question 4

all molecules of matter are in _____________ motion

Answer 4

constant

Question 5

the __________________ an object is, the faster its molecules move

Answer 5

warmer

Question 6

the state of matter that has constant volume but can flow and change its shape

Answer 6

liquid

Question 7

the state of matter with no definite volume or shape

Answer 7

gas

Question 8

the attraction between molecules or atoms to the same kind of molecule or atoms

Answer 8

cohesion

Question 9

attraction between molecules of different substances

Answer 9

adhesion

Question 10

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 10

surface tension

Question 11

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

Answer 11

meniscus

Question 12

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

Answer 12

capillarity

Question 13

the force exerted per unit of area

Answer 13

pressure

Question 14

the SI unit of pressure; equal to one Newton per square meter

Answer 14

Pascal

Question 15

pressure caused by gravity pulling on a substance; it is felt equally at every point

Answer 15

gravitational pressure

Question 16

the 2 factors that affect gravitational pressure

Answer 16

the depth of the liquid and fluid density

Question 17

states that a pressure increase applied to a fluid inside a closed container will be distributed equally throughout the container

Answer 17

Pascal’s Principle

Question 18

discovered Pascal’s Principle

Answer 18

Blaise Pascal

Question 19

a device that uses Pascal’s principle to multiply force by using a small-diameter input piston and a large diameter output piston connected by a liquid filled reservoir

Answer 19

hydraulic press

Question 20

The work output can never be _______________ than the work input

Answer 20

greater

Question 21

the increase in force provided by a hydraulic press can occur only at the expense of ____________________

Answer 21

distance

Question 22

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

Answer 22

compressibility

Question 23

states that a gas’s volume and pressure are inversely proportional when temperature is held constant

Answer 23

Boyle’s law

Question 24

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

Answer 24

Charles’s law

Question 25

states that gas temperature and pressure are directly related when volume is held constant

Answer 25

Amonton's law

Question 26

true/false: pressure is generated by the force of all the collisions of gas molecules with the container walls

Answer 26

true

Question 27

the gravitational pressure of air

Answer 27

atmospheric pressure

Question 28

the person that proposed that air has weight and therefore exerts pressure; they are credited with the discovery of air pressure

Answer 28

Evangelista Torricelli

Question 29

empty space with no matter

Answer 29

vacuum

Question 30

a device used to measure air pressure

Answer 30

barometer

Question 31

scientists who study weather

Answer 31

meteorologists

Question 32

true/false: mercury barometers have 0 disadvantages

Answer 32

false; they do have disadvantages

Question 33

uses an airtight metal box with thin flexible walls to measure pressure

Answer 33

aneroid barometer

Question 34

a device used to measure altitude

Answer 34

altimeter

Question 35

the Greek mathematician that discovered that fluids exert a buoyant force upon objects within them

Answer 35

Archimedes

Question 36

an upward force exerted by a fluid on a solid object placed in fluid

Answer 36

buoyancy

Question 37

states that buoyant force experienced by an object is exactly equal to the weight of the fluid displaced

Answer 37

Archimedes' principle

Question 38

a device used to measure the specific gravity of liquids

Answer 38

hydrometer

Question 39

a technique that uses Archimedes’ principle to determine the specific gravity of a solid denser than water

Answer 39

hydrostatic weighing

Question 40

true/false: an object in a fluid will float if it is lighter than an equal volume of the fluid and will sink if it is heavier than an equal volume of fluid

Answer 40

true

Question 41

a vessel that can float on top of or maneuver beneath the surface of water by changing its buoyancy

Answer 41

submarine

Question 42

the state in which the weight of a submerged object equals the weight of the displaced fluid

Answer 42

neutral buoyancy

Question 43

don't know why we need to know this one but: a flexible, gas-filled sac that allows a fish to control its buoyancy

Answer 43

swim bladder

Question 44

true/false: Archimedes’ principle is restricted to liquids and does not apply to objects immersed in any fluid, including gases

Answer 44

false; Archimedes’ principle is not restricted to liquids but applies to objects immersed in any fluid, including gases

Question 45

the type of small airship used for various applications not requiring great speed or robustness

Answer 45

blimp

Question 46

true/false: the thinning of the atmosphere with increased elevation limits the height that airships can attain

Answer 46

true

Question 47

fluid friction that tends to slow an object moving through a fluid, increasing air resistance

Answer 47

drag

Question 48

4 things affecting drag

Answer 48

Shape, size, speed, and density

Question 49

the science of shaping objects to allow the smooth flow of fluids around them and reduce drag

Answer 49

streamlining

Question 50

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

Answer 50

lift

Question 51

a structure designed to produce lift as it moves relative to a fluid

Answer 51

foil

Question 52

the angle of a foil relative to the fluid flow

Answer 52

angle of attack

Question 53

the angle at which maximum lift is achieved

Answer 53

critical angle of attack