2.2 (25Q) Flashcards
1
Q
What is newtons 1St law?
A
States a body will remain at rest continue to move in a uniform velocity unless acted upon by a force
2
Q
What is the metric and imperial system in newtons 1st law?
A
Metric - force -newtons
Imperial - force - pounds
3
Q
In newtons 1st law what will happen when a resultant force is acted upon on a body?
A
It will begin to move
4
Q
In. newton’s 1st law what will happen when a body is moving and a force acs on it?
A
It may alter is speed or direction motion or bring it to rest
5
Q
What quantity is force?
A
Vector
6
Q
What is a moment?
A
A turning effect produced by a force acting at a distance in respect from the objects fulcrum
7
Q
What is the equation for force?
A
F = M*A
8
Q
What is moment used for?
A
Static applications
9
Q
What is the metric and imperial measurements for moments?
A
Metric - moment - Nm
Imperial - moment - li-in
10
Q
What is an opposing moment?
A
Total moments that act against each other are applied at points separately by a distance
11
Q
What is an opposing moment?
A
Total moments that act against each other are applied at points separately by a distance
12
Q
In opposing moments what is the lever?
A
It is a ridged bar capable of turning about a fixed axis called a fulcrum
13
Q
What is fulcrum and what forces does it have?
A
Fulcrum is C
Has force F1 and F2 acting downwards
14
Q
Forces are what from the fulcrum?
A
Perpendicular distance from the fulcrum and apply two moments clockwise and anti clockwise
15
Q
What is the equation for opposing moments?
A
M1 = F1 * s1
16
Q
What is M1, F1, S1, M2, F2, S2?
A
M1 = total anti clockwise moment
F1 = force left on left hand side of the fulcrum
S1 = perpendicular distance from the fulcrum
M2 = total clockwise moment
F2 = force on the right hand side of the fulcrum
S2 = perpendicular to the fulcrum
17
Q
What is a couple?
A
A pair of forces that are equal in magnitude and opposing direction
18
Q
In couples where is the force applied?
A
Applied at points separated by distance perpendicular to the forces
19
Q
In a couple what does the combined moment of the forces produce?
A
Torque on the object they act on
20
Q
What is the equation for couples?
A
T = F * S
T = F * R * 2
21
Q
What does T, F, S, R, ?
A
T = torque
F = one of the forces
S = distance between the the forces
R = radius
2. When the force is a couple
22
Q
What is the resultant?
A
When two or more vectors acting on an object is known as the resultant
23
Q
Two vectors are the components of what?
A
The results if forces are in the same direction then add them together
24
Q
How do you find the resultant of 2 vectors?
A
Vectors that act in opposite directions along the same line
25
How do you calculate the resultant if they are on the same line.
Take the bigger number away from the smaller number
26
What is the Pythagoras theorem?
The hypotenuse is the resultant and equals the length and magnitude of the resultant
27
In Pythagoras theorem what does the angle between the resultant and vector indicates what?
Direction of the resultant
28
If the angle is between 90 degrease what can the resultant be calculated using?
Calculated using Pythagoras theorem
29
What is the equation for Pythagoras theorem?
A2^2+ B^2 = C^2
30
What is the parallelgram msthod?
The angle indicates the direction of the resultant
31
Scalar is what?
Have magnitude with no direction
32
What is vector?
Have magnitude and direction
33
Can scaler quantities undergo a change in direction?
Yes
34
Vectors act in what?
In a straight line
35
How vectors represented?
In diagrams with arrows that point in the direction of the force
36
What does the arrows length identify?
Measure the magnitude of a vector quantity
37
What is the CG of an object?
The imaginary point through which all the weight of an object is set to act
38
The CG is the average location of what?
The total of weight and therefore the balance point of an aircraft
39
Position of the CG is a given from what?
A given distance from the aircraft datum
40
Once datum has been selected what is taken from there?
All moment arms and location of CG range
41
Stress describes what?
Magnitude of force that causes deformation
42
Deformation is also known as what?
Strain
43
Stress is accompanied by what?
Strain
44
What is the metric and imperial measurements for stress?
Metric -pascal or N/M ^2
Imperial - PSI
45
Every part of the fuselage must carry what?
Must carry a load
46
Every part of the fuselage must carry what?
Must carry a load
47
What is the equation for stress?
A(stress) =F (force) / A(area)
48
What are the 5 basic structural forces on an aircraft?
Tension
Compression
Shear
Bending
Torsion
Tension
49
What does strain describe?
Deformation of a material due to stress
50
What is the equation for strain?
E (strain) = change in length / original length of the materiel
51
What is elasticity?
The ability of a material to return to its original shape one external forces have been removed
52
In elasticity why can internal forces be stretched but not broken?
They have internal atoms binding forces
They act like springs
53
What is plasticity?
Ability of a material to change shape permanently when subjected to stress
54
In placidity does the material return to its original shape once the force has been removed?
No remains deformed
55
What is tension?
The stress being applied which tends to increase the length of a body
56
What is tension or tensile strength also known as?
Axial or normal stress
57
As tension increases what will also increase?
Deformation will increase
58
What is hokes law?
The extension of an elastic object is directly proportional to the force applied to it
59
What is the equation for homes law?
F (force) = k (spring constant) * e (extension)
60
The equation works as long as what?
As long as the elastic limit is not extended
61
If an object is stretched to fan in hooked law what will happen?
It will not return to its origami oak shape when the load is removed
62
When an object meets the elastic limit what region does it enter?
Enters the plastic region
For and deformation and no proportional but increase in force give large deformation
63
In the plastic region what happens be for the rod breaks?
Diameter be What is tension or tensile strength also known as?comes smaller
Rod is about to fail
Rod fails
64
The elasticity of an object depends on what?
Shape
Size
Structure
65
What is young’s modal?
A way of measuring the elasticity of solids to compare different materials
66
What is compression?
Is the force applied which tends to shorten or squeeze a body
67
What is the compressive strength of a measured in?
N/m^2
68
What is shear?
Shear tries to slice a body apart sliding one layer over another
69
In an aircraft control system what is designed to withstand shear loads?
Clovis bolt
70
What is bending?
Force that tries to bend the aircraft’s wing upwards
71
What is torsion?
A twisting force
72
What happens when a an object is subjected to torsional stress?
Tension stress opperated diagonally across the object
73
Compression stress acts at what angle to tension stress?
Acts at a right angle
74
What is hardness?
Tendency to resist indentation or penetration
75
Hardness does not make a matirial resistant to what?
Resistant to fracture
76
What is strength?
Tendency to withstand an applied load without failure or plastic deformation
77
What is roughness?
Ten dances to resist breakage when deforming or when impact forces are applied to the matirial
78
What is brittleness?
The tendency to break without change of shape
79
When do more materials become brittle?
When they are cooled
80
What is elasticity?
Tendency to return to the original shape when the distorting force is removed
81
What is placidity?
The tendency to remain in the new shape when distorting force is removed
82
Can some hard substances can be plastic?
Yes but need much more force to change there shape
83
What is malleability?
The Brendan ey to undergo compressive stresses without damage
84
What is ductility?
Tendency to undergo tensile stress without damage
85
A fluid is a substance that does want?
Flows
86
What is a vapour?
Is a gas that can be liquified by an increase in pressure without decreasing its temperature
87
What is a volatile liquid?
A liquid which eisly evaporates
88
What is flammable and inflammable?
A material that will catch fire readily and vapours are usually highly flammable
89
What is flash point?
The temp at which it will catch fire when exposed
90
What is toxicity?
Refers to how poisonous it is
91
How are highly toxic materials identified?
By warning notices on there container
92
How are highly toxic materials identified?
By warning notices on there container
93
What is an inert substance?
A substance that will not chemically combine with another substance
94
All inert substances are at what presure and temperature?
At normal pressures and temperatures
95
When a force is spread out over an area it is said to exert what?
Pressure on the area
96
What is the metric and imperial system from pressure?
Metric - pressure - N/M^2 or Pa
Imperial - pressure - psi
97
What is the equation for pressure?
P (pressure) = F (force) / A (area)
98
What is 1 atom in pascals, psi, millibars?
Pascals - 101325 Pa
PSI | 1.7 lb/in
Millibars - 1013.25 mb
99
What is atmospheric presure measured with?
A mercury barometer
100
What is a mercury barometer?
A glass turbo closed st the top sitting in an open mercury filled basin at the bottom
101
What does the weight of the mercury creates?
Vacuumein the top of the tube known as a Torricellian vacuumed
102
What happens to the mercury vacuums with a change in atmospheric presure?
It will cause the mercury to rise or fall so height of the mercury in the column is proportional to atmospheric pressure
103
What happens to the mercury vacuums with a change in atmospheric presure?
It will cause the mercury to rise or fall so height of the mercury in the column is proportional to atmospheric pressure
104
What is gauge pressure?
Amount of pressure which is measured pressure in a fluid execs that of the atmosphere
105
What does ambient pressure refer to?
Presure in the area immediately surrounding an object
106
What is absolute pressure?
The process of having nothing inside a space
(A perfect vacuum)
107
What is the equation for absolute pressure?
P abs (absolute presure) = P g (gauge pressure) + P atm ( atmospheric pressure)
108
When the atmospheric pressure is 15 lb/in ^2 what is the absolute pressure and gauge presure for a perfect vacuum, outside air, cabin pressure on ground?
Perfect vacuum - absolute 0 - gauge -15
Outside Air - absolute 15 - gauge
Cabin pressure on ground - absolute 21 - gauge 6
109
What does Archimedean printable state?
A body in a a fluid will be subjected to an upward force equal to the weight of the fluid it displaces
110
What is the boy ant force equal to?
The weight of the fluid displaced
111
What is the equation for buoyancy’?
B (buoyant force) = W fluid (weight of the fluid displaced)
112
What will decide if an object will float?
By the density of the body and the fluid
113
What will decide if an object will float?
By the density of the body and the fluid
114
What is the ratio for buoyancy?
= P1 / P2
P1 =density of the body
P2 = density of the fluid
115
What is motion?
Continuing change of position or the process which a body undergoes displacement
116
Describe motion and uniform?
Motion - in different points in space at different times
Uniform - remains in the same point for a given period of time
117
Describe constant velocity?
When a body is moving in a straight line with a constant speed it is not acselerating so has constant velocity
118
What does S U V A T H G stand for?
S - displacement (m)
U - initial velocity (M/s)
V - final velocity (M/s)
A - acsellaration (m/s^2)
T - time (s)
H - height (M)
G - gravitational acselaration (M/s^2)
119
Can acselaration remain constant?
There is no special case where it remains constant
120
What does uniform circular motion describe?
An object travailing at a constant speed in a circular path a distance from the centre of rotation
121
In centripetal force the speed of the object remains the constant but what is constant ally changing?
Velocity is constant ally. Hanging because of the constant change of direction
122
The constant ally changing velocity means what?
There is constant acselaration
123
Centrifugal force will be perpendicular to what?
The direction of travel
124
What does Newton’s first law tell us about a satalite?
The satellite would naturally follow a straight path and the force must be applied for it to deviate from a straight path
125
Centripetal force is what force?
The force that is necessary to keep an object moving in a curved path and is directed towards the centre around the mass rotates
126
What is centripetal acceleration?
A constant speed in the direction of the motion
127
What way does centripetal force pull?
In words
128
Centrifugal force is a fictitious force that appears to do what?
Act on an object moving in a curved path when viewed from the same point of reference
129
What does inertia do in centrifugal force?
Makes an object moving in a curved path it gives it a tendency to continue moving in a straight line
130
What is a pendulum?
A weight suspended in the earths gravitational field which is free to pivot
131
What does a pendular motion describe?
The movement which the pendulum will undergo if it’s given a small displacement from its vertical position
132
What is angular displacement?
Angular displacement from rest to max swing position
133
What is oscillation/vibration?
One complete swing to and from maximum position
134
What is length of pendulum?
Distance from the pivot to the centre of gravity to the bob
135
What is a cycle?
The motion completed in one period
136
What is a cycle?
The motion completed in one period
137
What is frequency?
Number of cycles completed unit time
138
What do observations in pendular movements show?
That the pendulum has only displaced a few degrease
The periodic time remains constant even as the movement slows down
Mass of the bob makes no difference to periodic time
139
What is the relationship between length and periodic time?
The square of the periodic time is proportional to the length of the pendulum
140
The period of a pendulum increases when what happens?
When there is an increase in pendulum length or decrease in gravity
141
What is damping?
Is a decrease of vibrations as a result or removing energy through resistance to motion reducing the amplitude of the oscillation
142
What does vibration refer to?
Mechanical oscillations about an equilibrium point
143
Why will vibrations be desirable?
Because instances of vibration are necessary for the correct function of various devices
144
Why will vibrations be desirable?
Because instances of vibration are necessary for the correct function of various devices
145
Why are some vibrations undesirable?
They can cause imbalances in rotating parts
146
Sound and vibration are closely related in what?
Science of acoustics
147
What is free vibration?
When a mechanical system is set off with an initial input and then allowed to vibrate freely
148
What is forced vibration?
Occurs when a continuous force or motion is applied to a mechanical system
149
What is forced vibration?
Occurs when a continuous force or motion is applied to a mechanical system
150
In forced vibration the frequency of the vibration is dependant on what?
The frequancey of the force or motion applied
Amplitude vibration is strongly dependant on the behaviour of the mechanical system
151
What are harmonics?
Periodic vibrations
152
The motion of harmonics is periodic explain why?
The periodic motion repeats itself at standard intervals in a specific manner being sinusoidal with a constant amplitude
153
A simple frequancey travelling will take what shape?
Take form of a sin wave
154
If the periodic motion is the form of a travelling wave what quantities have to be taken in to account?
Velocity of propagation and wavelength
155
Harmonics are waves with a frequency that is what?
Positive integer multiple of the fundamental frequancey
156
Harmonics are waves with a frequency that is what?
Positive integer multiple of the fundamental frequancey
157
What is the fundamental frequency?
The first harmonic of the harmonic series
158
What is resonance?
The tendency of a system to oscillate at a maximum altitude at a cirtian frequency
159
What does 1Hz equal?
1 cycle per second
160
Resonance is important where?
Mechanical and electrics
161
What is the velocity ratio?
How far the effort has to move in relation to the load
162
If a machine has a velocity ratio grater than 1 the distance is moved by what?
Distance moved by the point of effort is grater than the distance moved by the load
163
What is mechanical advantage?
The ratio of the force produced by a machine to the force applied to it
164
What is the actual mechanical advantage?
The ratio of the output force and the input force
Actual mechanical advantage tells us how much easier the work can be done
165
What is the ideal mechanical advantage?
The mechanical advantage that would exist if there was no friction in the machine
166
What is a lever?
A ridged bar capable of turning about the fulcrum
167
What are the types of levers?
First class levers
Second class levers
Third class levers
168
In a first class lever where is the fulcrum?
Located between the the effort and resistance
The difference can be varied to suit the need
169
In a first class lever when an effort is applied it acts in what direction.
In the opposite direction to the resistance
170
Where is the fulcrum on a sec on class lever?
Fulcrum is at the end of the lever and the effort is applied at the opposite end
171
Where is the fulcrum on a sec on class lever?
Fulcrum is at the end of the lever and the effort is applied at the opposite end
172
What is the most common second class lever?
The wheelbarrow
173
When would a third class lever be used?
When the load is to be moved further than the load
174
Where is the force applied on a third class lever?
Between the fulcrum and the resistant load
175
What is an incline plane?
Plane surface incline to a horizontal plane at any angle but a right angle
176
What is a pulley?
It is a wheel or a set of wheels which has a rope or chain attached to lift or lower heavy objects
177
What is the mechanical advantage of a fixed pulley?
1
178
If a single pulley is not fixed what will its mechanical advantage be?
2
179
What is a common way to determine the mechanical advantage?
Count the number of ropes that move or support a movable pulley
180
A mechanical advantage of a pulley system is gained how?
The distance on which the effort is applied increase
181
What is a block and tackle?
A pulley system made up of a fixed and movable pulley with a rope or cable threaded between them
Has a mechanical advantage of 3
182
What do you do to gain a mechanical advantage on gears?
The number of teeth on the drive or the driven gear is varied
183
When will they be no mechanical advantage in gears?
When the drive and the driven gear have the same ammount of teeth
184
What is the equation for mechanical advantage?
MA = driven gear / drive gear
185
Torque is proportional to and inversely proportional to what?
Proportional to horsepower
Inversely proportionately to rotational speed (RPM)
186
What is the equation for horsepower?
Horsepower = torque * rpm / 5252
187
What must happen if torque increases or decreases?
If torque increases RPM must decrease
If torque decreases RPM must increase
188
What are spur gears?
Teeth cut straight across there circumference and used to connect parallel shafts
189
If both shafts turn in the same direction what is needed?
One gear must have internal teeth
190
What is a bevel gear?
Teeth cut in to a conical surface known as the pitch zone
Two gears mesh together to transmit power between two shafts
191
What is a worm gear?
A gear consisting of a toothed wheel wired by a short revolving cylinder
192
What are sun and planetary gears?
The input drive is on the sun gear
Planets held together by a cage driven around by the sun gear
Used when weight and apace are an issue
193
What is efficiency?
The ratio of work which is transferred to a useful form compèred to the total input work
It is measure in percentage
No machine can be 100% efficancey due to heat
194
What does Newton’s first law state?
Every object remains in a state of rest or in uniform motion in a straight line unless it is made to change that state by external forces impressed on it
195
Newton’s first law is also called what?
The law of inertia
196
What does Newton’s second law describe?
Acceleration of an object produced by a force is directly proportional to the force in the same direction as the force and is inversely proportional to the mass of an object
197
What does Newton’s second law state?
Force =mass * acselaration
198
What is newtons 3rd law
Every action has an equal and opposite reaction
199
What is mass?
Amount of matter in a body
200
What is mass?
Amount of matter in a body
201
What is force?
Force is an interaction that changes a body’s state of rest or uniform motion in a straight line
202
What is inertia?
Property of matter that cause interaction any change to its motion
203
Inirtia of a body depends on what?
On mass
The grater the mass the grater the inertia
204
Inirtia of a body depends on what?
On mass
The grater the mass the grater the inertia
205
What is work?
Is force causing a movement or displacement of a i jest
206
What is power?
Measure of the rate at which work is done or when energy is converted
207
What is energy?
Capacity to do work
208
What is energy?
Capacity to do work
209
What is potential and kinetic energy?
Potential energy - energy a body has due to its position or condition
Kinetic energy - work needed to acselaration a body of mass from rest to velocity
210
What is total energy?
The sum of all different forms of energy in a system
211
What is chemical energy?
The energy which is stored in chemical bonds between atoms
The energy can be realised or consumed
When bonds are broken new bonds are formed
212
What is heat energy?
Energy which a body possesses
Also called internal energy
Can be transferred between bodies
213
What is efficiency?
Defined as the ratio of useful work done by the machine
214
What is the impulse?
Impulse of a force changes the momentum of a body and is equal to the force multiplied by the time it acts on the body
215
What amounting is a vector?
Vector
216
What is a gyroscope?
An instrument that contains a disc rotating at a axis at high speeds
217
What is rigidity?
Application of newtons 1st law
Ability of a spinning rotor to retain its axis in a fixed direction in space unless acted upon by an external force
218
What is rigidity?
Application of newtons 1st law
Ability of a spinning rotor to retain its axis in a fixed direction in space unless acted upon by an external force
219
The redigity of a spinning rotor is affected by what factors?
Rotor mass
Effective radius at inch the mass acts
Speed of rotation
Bering friction
220
What is prosession?
If an external force is applied to change the direction of the rotor spin axis the gyro resists the change in move as the force right angles to the direction originally applied
221
The simplest form of gyro only consists what.
Rotor
222
The simplest form of gyro only consists what.
Rotor
223
What is friction?
Force resisting the realities motion of materials rubbing against each other
224
What is starting friction?
Can also be called static friction
Present when a body has been at rest
Present when a body begins to move under rest
Can be referred to as break away force
225
When an attempt is made to move an object what must be done first?
It must be broken lose or started
226
What is sliding friction?
Sliding friction is present as a body slides over another surface
Resistance to motion offered by an object has been set in motion
Amount of sliding friction depends on the nature on the nature of the nature of matirial surface
227
What is sliding friction?
Sliding friction is present as a body slides over another surface
Resistance to motion offered by an object has been set in motion
Amount of sliding friction depends on the nature on the nature of the nature of matirial surface
228
What is rolling friction?
Present between a rolling body and the surface on which it rolls
Resistance is gravely reduced if an object is mounted on wheels or rollers
Much smaller than sliding friction
229
What has a different coefficient of friction?
Every pair of flat surfaces
230
Coefficient efficient of sliding friction are less than what?
Less than the starting coefficient of starting friction
231
What does density describe?
How closely packed the particles are in are in a solid, liquid, gas
232
What does density depend on?
The matirial
233
Scientists can measure how tightly packed particals are how?
Measuring the mass of a certain volume of the matirial
234
What is the equation for density?
Density = mass / volume
235
To convert kg/m^3 to g/cm^3 what do you do?
Divide by 1000
236
To convert g/cm^3 to kg/m^3 what do you do?
Times by 1000
237
What is a hydrometer used for?
To determine the septic gravity of an electrolyte in an aircraft battery
238
When the battery is discharge the calibrated float will indicate what?
Approximately 1150
239
What is the indication of a charged battery?
1275 and 1310
240
The electrolyte in a distachrqged battery will be more dense that’s what?
1.5 times more dance than water
241
What is viscosity?
Resistance of a fluid to change in shape or relative movement of neighbouring portions within the fluid
242
Viscosity denotes as what?
Opposition to flow and is caused by the internal friction between monocles
243
What is the equation for viscosity?
Viscosity = pascals * second
244
What is the equation for viscosity?
Viscosity = pascals * second
245
Viscosity is a major factor in determining what?
The forces that need to be overcome when fluids are used in lubrication or transported in pipelines
246
What will determine how the air will flow around an aircraft?
Viscosity
Density
Compresabillity
Air temperature
247
What will determine how the air will flow around an aircraft?
Viscosity
Density
Compresabillity
Air temperature
248
When would the viscosity of a fluid decrease?
With an increase in tempreture
249
What is fluid resistance?
It occurs when a solid travels through a liquid or a gas
250
What are the factors that determine amount of fluid resistance on a solid objects?
Viscosity of the fluid
Surface
Texture
Shape
251
What does streamlining mean?
Decreasing the amount of restrictive force of fluid friction
252
If a liquid is compressible what will happen?
There I’ll be an increase in pressure and it will rise the fluids internal temperature and reduce its viscosity so velocity will increase
253
The pressure in fluid pressure is exerted by what?
A column of liquid determined by the high of the column and the the of fluid
254
What is the equation for fluid presure?
Pressure = force / area
255
What is the equation for fluid presure?
Pressure = force / area
256
What is the equation for fluid presure?
Pressure = force / area
257
What does pascals law explain?
That when pressure is applied to a contained liquid the liquid exerts an equal pressure at right angles
258
What is pascals law equation?
Force = area * pressure created bay the fluid
259
How is the formula for force produced by a hydronic piston calculated?
By taking in to account the area of the piston that is subjected to pressure
260
What is static pressure?
Exists in addition to dynamic factors that may also present at the same time
261
What is static pressure?
Exists in addition to dynamic factors that may also present at the same time
262
What is dynamic pressure?
The pressure that emerges form velocity of the fluid in motion
263
What is dynamic pressure?
The pressure that emerges form velocity of the fluid in motion
264
What is total pressure?
The sum of static and dynamic pressure
265
What is Bernoulli’s printable?
Printable that explains the relationship between potential energy and kinetic energy
266
In Bernoulli’s printable what is potential energy caused by?
The fluids total pressure
267
What is kinetic energy caused by?
The fluids movement
268
What does Bernoulli’s printable state?
When energy it not added or taken away from a fluid in motion the potential energy and presure will decrease when kinetic energy and velocity increases
269
Where is a Venturi tube narrower?
Narrower in the middle
270
Where is a Venturi tube narrower?
Narrower in the middle
271
What happens when fluid in the Venturi tube enters the narrower section?
Presure decreases
Velocity increases
272
Will the rate (volume per second) remain the same through the entire Venturi tube?
Yes it remains constant
273
What are the three forms of energy within the moving fluid in a Venturi tube?
Gravitational potential energy of the particals
Pressure energy
Kinetic energy
274
Pressure energy is what?
Energy stored in a fluid due to the force per area applied to it
