AP Physics chapters 3-5

surface tension

liquids resistance to increase its surface area

meniscus

curved surface of a liquid

hydrostatics

study of liquids at rest

force

any push or pull on an object

normal force

any force that is perpendicular to a surface

pressure

force per unit area

law of liquid pressure

the downward pressure on a surface at constant depth

pascal’s principle

The pressure applied to any surface of a confined liquid is equally transmitted in every direction throughout the liquid

hydraulic device

any device that uses a confined liquid to multiply force

when you increase flow you sacrifice

distance

bouyant force

reduces the apparent weight of a submerged object

archimedes principle

The buoyant force acting upon a body submerged in liquid is equal to the weight of the liquid displaced by that body

hydrodynamics

the study of liquids in motion

viscosity

a liquids resistance to flow because of molecular attraction

flow rate and viscosity are ? related

inversely

poise

relates the force per unit area necassary to move a layer of liquid in one second to a distance equal to its thickness

poise ? viscosity

measures

cavitation

production of tiny vapor bubbles within the liquid

laminar flow

ideal liquids’ tendency to flow in straight lines throughout the cross-sectional area

all ideal liquids are…

incompressable and have a uniform density

eddy currents

swirl against the flow of a liquid due to friction between the liquid and the pipe; produced by a real liquid

principle of continuity

states that the volume flow rate at any two points in a pipe must be constant 

volume flow rate

measures the total volume of a liquid flowing past a point in one second

bernoulli’s principle

inverse relationship between lateral pressure and velocity squared; lateral pressure decreases while the rate of flow increases

lateral pressure

pressure on the walls of the channel

air pressure

bombardment of air molecules

warmer molecules of air exert more…

force

More molecules of air create more…

force

air pressure is dependent upon…

temperature and number of molecules

vacuum

total absence of air or any other matter

fluids

any substance capable of flowing

airfoil

any object designed to create lift into the air

horror vacui

says that nature fills any empy space with the nearest matter it can find; overturned

toricelli

credited with the first baromeerr

standard atmospheric pressure

The pressure that will support a mercury column exactly 760mm tall when the temp is 0 degrees

1atm is equal to…

760 torr

guage pressure

The difference in height between the columns 

mercury barometers

can see small things

absolute pressure

guage pressure must be added to or subtracted from 1atm

aneriod

without liquid

inverse proprotion

When one quantity increases, the other decreases

boyle’s law

Volume is inversely proportional to pressure at a constant temperature and the same number of molecules

absolute zero

lowest temperature at which matter can exist

absolute temperature

temperature expressed in kelvin

direct proportion

as one quantity increases, the other on increases

charles law

volume and temperature are dierctly related

combined gas law

boyle’s and charles’ laws put together

avagadro’s law

at a given temp and pressure, two gases of same volume have the same number of molecules 

universal gas constant

constant pf proportionality (R)

ideal gas law

relates ideal gases with temperature, pressure, and volume

pneumonic device

any device that transports air or is driven by air pressure

entrained

fluid that is caught up and carried along by a fluid stream nearby

siphon

simple device for transferring liquid from a higher container to a lower container

elasticity

the ability to recover their original shape after being deformed by an extrenal force

rigidity

the tendency to resist flexing or deforming

resilience

amount of deformation required to bring a material to its elastic limit

elastic limit

the point past which a material will not recover its original shape

plasticity

maximum amount of relative deformation that may be permanantly imposed upon it 

mechanical working

various prosses used to impose desired shapes upon ingots of newly refined metal

forging

metal squeezed or pounded with great force between two dies

rolling

metal is pressed down by a series of paired, heavy rollers into a continuous sheet

malleability

propery of a metal to be rolled or hammered into a sheet

drawing

metal is pulled through a single die into a continuous ribbon with the same cross sectional shape as the interior surface of the die

ductility

property of metals that allow them to be drawn

hook’s law

states that the wire pulling upwards is proportinal to its displacement downwards and that the restorative force acts in the opposite direction of the displacement

tensile force

the stretching or compressing force of the load

stress

deformative tensile force per unit cross sectional area

strain

ratio of change compared to the original length

tensile stress

happens when a tensile force is perpendicularly applied to the cross sectional area of a stressed object

tension

the effect due to pulling a rod along its length

proportional limit

the restorative force in the wire is no longer a linear function of elongatio; when hook’s law completely breaks down

elastic limit

maximum stress the material can sustain without permanately being deformed; maximum stress

ultimate tensile strength 

maximum stress te materal can sustain without breaking

breaking point

maxiumum strain tolerated by the wire

tensile strength

ultimate tensile strength

brittle

break suddenly under a load instead of deforming first

equilibrium

the distance where there is no net attraction or repulsion

shear

combination of two oppositely directed forces along parallel lines of action

volume stress

stress that causes bulk deformation