2.2.1 Statics Flashcards
The pressure of still air is referred to as:
Static pressure
The static pressure of the atmosphere surrounding an object of interest may also be called:
ambient pressure
Force is a vector quantity, so it has both
Magnitude and direction
The SI unit of force is the
Newton (N)
Moment (Nm) =
Force (N) x Perpendicular distance (m)
The turning effect of a force is called a
moment
A ____ is a rigid bar capable of turning about a fixed axis called the _____
lever
fulcrum
A ‘couple’ results from two equal forces acting in ____ but _____ directions on two different points of a body
parallel
opposite
The effect that results from two or more vectors of the same type of quantity acting on an object is known as the _____
Two or more vectors that combine to give a resultant are its _____
resultant
components
The centre of gravity (cg) of a body is the point about which it is _____ _____
perfectly balanced
When a material has a force exerted on it, the material is said to be _______ or in a state of ____
stressed
stress
Stress =
Force / C.S.A
The SI unit of stress is :
N/m^2
Pascal (Pa)
A bending force acts _____ to the length of an object
Perpendicularly
When a rod or a wire is pulled, it stretches and the total stretch or elongation, expressed as a fraction of the un-stretched length is called ____
strain
A solid is said to be _____ if it can readily be forced into a different shape ______ without fracturing eg paper clip
plastic
permanently
The plasticity of most substances _____ with _____
increases
temperature
A hard substance has a high _________ or any action tending to ____ its surface
resistance to indentation
penetrate
The ability to resist breakage when deforming or impact forces are applied to it is called
toughness
_______ materials can be beaten, rolled or pressed into shape without fracture
Malleable
______ substances break with little or no change of shape
Most substances get more _____ as they get _____
brittle
brittle
colder
A vapour is a gas that can be liquefied by an _____ in _____ without _____ its ______
increase
pressure
decreasing
temperature
A volatile liquid is one which readily ….
evaporates (vaporises) at normal temperature
The flash point of a combustible liquid is the …..
temperature it has to be before it will catch fire when exposed to a naked flame
Aviation gasoline has a flashpoint of about
- 43^C
All combustible liquids are very flammable when in the form of _____ or _____, regardless of flash point or temperature
mist
spray
The pressure produced by a column of liquid is directly proportional to the ____ of the columnm and in no way it depends upon either the shape of the container or the amount of liquid the container holds
height
The height of fluid above the level at which a pressure is taken is sometimes called a …..
‘head of pressure’
Pressure =
Unit of force / unit of area
Pressures measured as so much above a complete vacuum are said to be
absolute pressures
When we are only interested in the difference between two pressures the difference is referred to as a
differential pressure
The pressure of still air is referred to as
static pressure
The static pressure of the atmoshphere surrounding an object of interest may also be called
ambient pressure
Arhimedes principal states that when a body is immersed in a fluid, the apparent loss in weight equals ….
the weight of the fluid displaced
Aneroid comes from the Greek and means ‘’-__ ____’’ ie there is no fluid in it
The aneroid barometer consists of ______ ____ ____ with _____ ____
not wet
closed sealed capsle
flexible sides
When a barometer is used to measure height, it is called an
altimeter
An altimeter is an instrument that is used to indicate the height of the aircraft above a predetermined level, such as _______ or _____
sea level
terrain beneath the aircraft
Altimeters that measure the aircraft’s altitude by measuring the pressure of the atmospheric air are known as
pressure altimeters
A barometer is an instrument for measuring _______
atmospheric pressure
