Overview

Question 1

What is Mass ?

Answer 1

1. The quantity of matter in a body.’
2. The mass of a body is a measure of how difficult it is to start or stop.The larger the mass, the greater the FORCE required to start or stop it in the same distance. The unit is kg.

Question 2

What is force ?

Answer 2

A push or a pull’. That which causes or tends to cause a change in motion of a body. The unit is Newton.

Question 3

What is Weight ?

Answer 3

The force due to gravity’. ( F = m x g )

Question 4

What is Centre of gravity ?

Answer 4

= The point through which the weight of an aircraft acts.
 An aircraft in flight is said to rotate around its CG.
 The CG of an aircraft must remain within certain forward and aft limits, for reasons of both stability and control.

Question 5

What is work ?

Answer 5

A force is said to do work on a body when it moves the body in the direction in which the force is acting. The amount of work done on a body is the product of the force applied to the body and the distance moved by that force in the direction in which it is acting. Work = Force x Distance (through which the force is applied)

Question 7

What is power ?

Answer 7

Unit - Watt (W) - Power is simply the rate of doing work.Power (W) = Force (N) x Distance (m)/ Time (s)

Question 8

What is energy ?

Answer 8

Unit - Joule (J) - Mass has energy if it has the ability to do work. The amount of energy a body possesses is measured by the amount of work it can do. The unit of energy will therefore be the same as those of work, joules.

Question 10

Kinetic Energy

Answer 10

Unit - Joule (J) - ’’The energy possessed by mass because of its motion’. ’A mass that is moving can do work in coming to rest’. KE = ½m V2 joules.
- Doubling the velocity will have a greater impact on the kinetic energy than doubling the mass. (velocity is squared)

Question 11

Newton’s First Law of Motion

Answer 11

’A body will remain at rest or in uniform motion in a straight line unless acted on by an external force’.
To move a stationary object or to make a moving object change its direction a force must be applied.

Question 12

Inertia

Answer 12

‘The opposition which a body offers to a change in motion’. A property of all bodies. Inertia is a quality,hence it has no units. But it is measured in terms of mass, which is a quantity.
- The larger the mass, the greater the force required for the same result.
- A large mass has a lot of inertia.
- Inertia refers to both stationary and moving masses.

Question 13

Newton’s Second Law of Motion

Answer 13

’The acceleration of a body from a state of rest, or uniform motion in a straight line, is proportional to the applied force and inversely proportional to the mass’.

Question 14

Velocity

Answer 14

Unit - Metres per second (m/s). - ‘Rate of change of displacement’

Question 15

Acceleration

Answer 15

Rate of change of velocity’. A force of 1 newton acting on a mass of 1 kg will produce an acceleration of 1 m/s2.
- For the same mass; the bigger the force, the greater the acceleration.
- For the same force; the larger the mass, the slower the acceleration.

Question 16

Momentum

Answer 16

Unit - Mass x Velocity (kg-m/s) - ‘The quantity of motion possessed by a body’. The tendency of a body to continue in motion after being placed in motion.

Question 17

Newton’s Third Law

Answer 17

‘Every action has an equal and opposite reaction, provided that the force is acting on two different bodies’
- If a force accelerates a mass in one direction, the body supplying the force will be subject to the same force in the opposite direction.

Question 18

What is Control Reversal ? What are the two regimes in which it can occur ?

Answer 18

• At high speed: the displacement of a control surface producing a moment on the aircraft in a reverse sense because of excessive structural distortion.
• At low speed: the displacement of an aileron increasing the angle of attack of one wing to or beyond the critical angle, causing a roll in the direction opposite to that required.

Question 19

Critical Mach number (M CRIT

Answer 19

The free stream Mach number at which the peak velocity on the surface of a body first becomes equal to the local speed of sound.

Question 20

What is Damping ?

Answer 20

To slow down the rate; to diminish the amplitude of vibrations or cycles.

Question 21

Geometric Dihedral

Answer 21

The angle between the horizontal datum of an aeroplane and the plane of a wing or horizontal stabiliser semi-span.

Question 22

Eddy

Answer 22

An element of air having intense vorticity.

Question 23

Effective Angle of Attack (αe)

Answer 23

The angle between the chord line and the mean direction of a non-uniform disturbed airstream.

Question 24

Equilibrium

Answer 24

A condition that exists when the sum of all moments acting on a body is zero AND the sum of all forces acting on a body is zero.

Question 25

Fairing

Answer 25

A secondary structure added to any part to reduce its drag.

Question 26

Fillet

Answer 26

A fairing at the junction of two surfaces to improve the airflow.

Question 27

Flightpath

Answer 27

The path of the Centre of Gravity (CG) of an aircraft.

Question 28

Free stream velocity

Answer 28

The velocity of the undisturbed air relative to the aircraft

Question 29

Gradient (Pressure)

Answer 29

Rate of change in pressure with distance.

Question 30

Gust

Answer 30

A rapid variation, with time or distance, in the speed or direction of air.

Question 31

Laminar Flow

Answer 31

Flow in which there is no mixing between adjacent layers.

Question 32

Moment (N-m)

Answer 32

The moment of a force about a point is the product of the force and the distance through which it acts. The distance in the moment is merely a leverage and no movement is involved, so moments cannot be measured in joules.

Question 33

Nacelle

Answer 33

A streamlined structure on a wing for housing engines (usually).

Question 34

Pod

Answer 34

A nacelle supported externally from a fuselage or wing.

Question 35

Relative Airflow

Answer 35

- The direction of airflow produced by the aircraft moving through the air. The relative airflow flows in a direction parallel and opposite to the direction of flight. -Therefore, the actual flight path of the aircraft determines the direction of the relative airflow. Also, air in a region where pressure, temperature and relative velocity are unaffected by the passage of the aircraft through it.

Question 36

Scale Effect

Answer 36

If a 1/10th scale model is considered, all the linear dimensions are 1/10th of the real aircraft, but the areas are 1/100th; and if the model is constructed of the same materials, the mass is 1/1000th of the real aircraft.

Question 37

Shockwave

Answer 37

A narrow region, crossing the streamlines, through which there occur abrupt increases in pressure, density, and temperature, and an abrupt decrease in velocity. The normal component of velocity relative to the shock wave is supersonic upstream and subsonic downstream.

Question 38

Sideslip

Answer 38

Side-slip - Motion of an aircraft, relative to the relative airflow, which has a component of velocity along the lateral axis.

Question 39

Speed of Sound (a)

Answer 39

Sound is pressure waves which propagate spherically through the atmosphere from their source. The speed of propagation varies ONLY with the temperature of the air.

Question 40

Stagnation point

Answer 40

A point where streamlines are divided by a body and where the fluid speed is zero, relative to the surface.

Question 41

Viscosity

Answer 41

The resistance of fluid particles to flow over each other. All fluids have the property of viscosity.

Question 42

Vortex

Answer 42

A region of fluid in circulatory motion, having a core of intense vorticity, the strength of the vortex being given by its circulation.

Question 43

Vorticity

Answer 43

Generally, rotational motion in a fluid, defined, at any point in the fluid, as twice the mean angular velocity of a small element of fluid surrounding the point.

Question 44

Wash-out

Answer 44

Decrease in angle of incidence towards the tip of a wing or other aerofoil

Question 45

Wing Loading

Answer 45

Ratio of aircraft weight to wing area. Wing Loading = Aircraft Weight/Wing Area

Question 46

Zoom

Answer 46

Zoom - Using kinetic energy to gain height.

Question 47

An aircraft’s mass is a result of:

Answer 47

How much matter it contains

Question 48

The definition of a force is:

Answer 48

A push or a pull

Question 49

Weight is the result of:

Answer 49

The force on mass due to gravity

Question 50

About which point does an aircraft rotate:

Answer 50

The centre of gravity

Question 51

If a force is applied to a mass and the mass does not move

Answer 51

No work is done

Question 52

The unit of work is called the: The unit of power is called the:

Answer 52

Joule, Watt

Question 53

If a force of 20 Newton’s moves a mass 5 metres:

Answer 53

the work done is 100 Nm, the work done is 100 Joules

Question 54

If a force of 50 Newton’s is applied to a 10 kg mass and the mass moves 10 metres and a force of 50 Newton’s is applied to a 100 kg mass which moves 10 metres:

Answer 54

The work done is the same in both cases

Question 55

The definition of power is:

Answer 55

The rate of doing work

Question 56

If a force of 500 Newton’s moves a mass 1000 metres in 2 mins, the power used is:

Answer 56

4167 Watts

Question 57

The unit of kinetic energy is the:

Answer 57

Joule

Question 58

When considering kinetic energy: 1 - a moving mass can apply a force by being brought to rest 2 - kinetic energy is the energy possessed by a body because of its motion 3 - if a body’s kinetic energy is increased, a force must have been applied 4 - kinetic energy = ½ m V2 joules The combination of correct statements is: a. 1 and 2 b. 1, 2, 3 and 4 c. 4 only d. 2 and 4

Answer 58

All are correct

Question 59

The property of inertia is said to be:

Answer 59

The opposition which a body offers to a change in motion

Question 60

Considering Newton’s first law of motion: 1 - a body is said to have energy if it has the ability to do work 2 - the amount of energy a body possesses is measured by the amount of work it can do 3 - a body will tend to remain at rest, or in uniform motion in a straight line, unless acted upon by an external force 4 - to move a stationary object or to make a moving object change its direction, a force must be applied The combination with the correct statements is: a. 3 and 4 b. 3 only c. 1 and 2 d. 1, 2, 3 and 4

Answer 60

3 and 4 are correct

Question 61

Considering Newton’s second law of motion: 1 - every action has an equal and opposite reaction 2 - if the same force is applied, the larger the mass the slower the acceleration 3 - if two forces are applied to the same mass, the bigger the force the greater the acceleration 4 - the acceleration of a body from a state of rest, or uniform motion in a straight line, is proportional to the applied force and inversely proportional to the mass The combination of true statements is: a. 1 only b. 1, 2, 3 and 4 c. 2, 3, and 4 d. 3 and 4

Answer 61

2,3,4

Question 62

The definition of velocity is the:

Answer 62

Rate of change of displacement

Question 63

When considering acceleration: 1 - acceleration is the rate of change of velocity 2 - the units of acceleration are metres per second 3 - the units of acceleration are kilogram-metres per second 4 - the units of acceleration are seconds per metre per metre The combination of correct statements is: a. 4 only b. 1 and 4 c. 1 only d. 1 and 2

Answer 63

1 only

Question 64

The definition of momentum is: a. The quantity of mass possessed by a body b. The quantity of inertia possessed by a body c. The quantity of motion possessed by a body d. The opposition which a body offers to a change in velocity

Answer 64

c

Question 65

A force of 24 Newton’s moves a 10 kg mass 60 metres in 1 minute, the power used is: 1 - 24 Watts 2 - 240 Watts 3 - Force times distance moved in one second 4 - Force times the distance the mass is moved in one second Which of the preceding statements are correct a. 1 and 3 b. 1, 3 and 4 c. 2 and 4 d. 4 only

Answer 65

1.3.4

Question 66

When considering momentum: 1 - Momentum is the quantity of motion possessed by a body 2 - Momentum is the tendency of a body to continue in motion after being placed in motion 3 - A mass of 2000 kg moving at 55 m/s has 110,000 kg-m/s of momentum 4 - A large mass moving at 50 m/s will have less momentum than a small mass moving at 50 m/s The correct combination of statements is: a. 1 and 3 b. 1, 2, 3 and 4 c. 1, 2 and 3 d. 2, 3 and 4

Answer 66

c. 1, 2 and 3