POF 01

1. The unit of mass is the: A) kilogram. B) newton. C) watt. D) joule.

2. The unit of weight is the: A) newton. B) kilogram. C) watt. D) joule.

3. Force is measured in: A) newtons. B) psi

4. Velocity is measured in _________ per _________. A) metres; second. B) feet; minute. C) metres; kilogram. D) watts; second.

5. Acceleration is measured in: A) m/s² B) m/s C) m D) newtons

6. The unit of energy is the: A) joule. B) kilogram. C) watt. D) newton.

7. The unit of density is the: A) kg/m³ B) kg/m² C) kg/m D) m/kg³

8. Pressure is measured in _________ per m². A) newtons. B) kilograms. C) watts. D) joules.

9. Absolute temperature is measured in _________. A) Kelvin B) Celsius

10. The unit of power is the: A) watt. B) newton. C) joule. D) kilogram.

11. A body will remain at rest or in uniform motion unless acted upon by an external force' is a statement of Newton's _________ law. A) First. B) Second. C) Third.

12. To each and every action there is an equal and opposite reaction' is a statement of Newton's _________ law. A) Third. B) First. C) Second.

13. Newtons 2nd Law states that: 'the acceleration of a body in a straight line is proportional to the applied _________ and inversely proportional to the _________ of the body'. A) force; mass. B) force; force. C) mass; mass. D) mass; force.

14. The rate of doing work is a description of: A) power. B) force. C) energy. D) Newton's Third law.

15. High pressure results in the molecules of a gas being forced closer together. This raises the __________ of the gas. A) density B) volume C) composition.

16. In a parcel of air, the density __________ with temperature. A) decreases. B) increases. C) stays the same.

17. The pressure exerted in all directions by a volume of stationary air is called __________ pressure. A) static B) dynamic

18. The symbol for density is: A) ρ B) σ C) φ

19. Density __________ with altitude. So, as altitude increases, for a given speed of flow, the dynamic pressure of a gas __________. A) decreases; reduces. B) decreases; increases. C) increases; reduces. D) increases; increases.

20. Air density is _________ to the absolute temperature of the air. Absolute temperature is measured in Kelvin. A) inversely proportional. B) proportional

21. Air density ∝ __________ A) p/T B) T/p

22. At constant temperature, the volume of a fixed amount of a gas is __________ to its pressure. A) inversely proportional B) proportional C) equal

23. Indicated airspeed is a measure of the __________ pressure sensed by the aircraft. A) dynamic B) static C) total

24. Study the diagram. Which of the following statements are correct: [Abbildung erforderlich: siehe Original-PDF, Seite 4. Grafik nicht in dieser CSV enthalten.] A) The dynamic pressure at A is lower than the dynamic pressure at B. B) The blue line depicts a streamline. C) The static pressure at C is greater than the static pressure at B. D) The fastest flow occurs at B. E) The shaded blue area represents a stream tube. F) The mass flow at A is the same as the mass flow at D. G) The flow velocity is greater at C than at B.

25. Study the diagram. Which of the particle flow paths is clearly impossible? [Abbildung erforderlich: siehe Original-PDF, Seite 5. Grafik nicht in dieser CSV enthalten.] A) C B) A C) B D) D

26. In relation to the flow of an ideal fluid through a venturi, the equation of continuity requires that the mass flow through the venturi__________. A) remains constant at all points. B) increases in the throat. C) decreases in the inlet to the venturi.

27. Stated mathematically, Bernoulli's equation is: Ps + ½ ρ V² = constant.In layman's terms, this equation states that in the flow of an ideal fluid the sum of the __________ energy and the kinetic energy must remain constant. A) pressure. B) total. C) flow. D) internal.

28. The point of origin of the total reaction is called the __________ __________ __________. A) centre of pressure B) centre of action C) centre of gravity

29. The total reaction points upwards and __________ relative to the 2-dimensional free stream flow. A) Backwards. B) Forwards.

30. The component of the total reaction which is parallel to the free stream flow, acting in the same direction, is called: A) drag B) lift C) thrust

31. Lift is the component of the total reaction which acts __________ to the relative air flow. A) perpendicular. B) normal. C) in the opposite direction.

32. An imaginary straight line drawn between the centre of the leading edge and the trailing edge is called the __________ . A) chord line B) camber line C) leading line

33. The ratio of the aerofoil’s maximum thickness to the length of its chord is called the __________ - __________ ratio. A) thickness; chord. B) chord; thickness. C) angle; chord. D) oblique; chord.

34. The point of maximum thickness of an aerofoil usually occurs: A) In the first 1/3 of the chord length. B) At the leading edge. C) Closer to the trailing edge than the leading edge. D) About half way along the chord length.

35. The mean camber line (or camber line) is an imaginary line half-way (equidistant) between: A) The upper and lower surfaces. B) The angle of attack and the chord line. C) The point of maximum thickness. D) The leading and trailing edges.

36. Camber describes the distance between: A) The mean camber line and the chord line. B) The point of maximum thickness and the lower surface. C) The distance between the leading edge and the trailing edge. D) The upper and lower surfaces.

37. The compression of the streamlines above the aerofoil indicates that the flow is __________ in this region resulting in a __________ in static pressure. A) faster; drop. B) slower; drop. C) faster; increase. D) slower; increase.

38. The dividing line between the upper and lower flows is known as the __________ . A) stagnation line B) compressibility line C) stagnation point

39. Study the diagram then identify which of the following statements are correct: [Abbildung erforderlich: siehe Original-PDF, Seite 7. Grafik nicht in dieser CSV enthalten.] A) The fastest flow occurs at E. B) D indicates one of the stagnation points. C) H is an area of relatively low pressure. D) The lowest pressure occurs at E. E) The speed of the flow is zero at G. F) B depicts downwash. G) The fastest flow occurs at D. H) F is an area of relatively low pressure.

40. Study the diagram then identify which of the following 6 statements are correct: [Abbildung erforderlich: siehe Original-PDF, Seite 8. Grafik nicht in dieser CSV enthalten.] A) A is the angle of attack. B) D is the chord line. C) B is the centre of pressure. D) C is drag. E) G is the relative airflow. F) F is the total reaction. G) E is the total reaction. H) F is lift. I) D is the relative airflow.

41. As angle of attack (alpha) increases, the velocity of the flow over the upper surface __________. A) increases. B) decreases. C) stays the same.

42. Increasing an aerofoil’s camber produces an increase in __________ pressure over the upper surface. A) dynamic B) static

43. Increasing an aerofoil’s camber produces __________ in static pressure over the upper surface. A) a decrease. B) an increase C) no change.

44. Increasing an aerofoil’s angle of attack produces __________ in static pressure over the upper surface and __________ in dynamic pressure over the upper surface. A) a decrease; an increase. B) an increase; an increase. C) a decrease; a decrease. D) an increase; a decrease.

45. The Lift formula is: L = ½ ρ V² S CL Study the diagram carefully. Identify which 4 of the following statements about the lift formula are correct. [Abbildung erforderlich: siehe Original-PDF, Seite 9. Grafik nicht in dieser CSV enthalten.] A) (½ ρ) is represented by property labelled C. B) V² is represented by the length of the vector labelled A. C) S is represented by the area identified by the letter B. D) CL is represented by the combination of the shape of D and the angle E. E) CL is represented by the shape of the area labelled D. F) CL is represented by the angle E.

46. Study the diagram then identify which 3 of the following statements are correct. [Abbildung erforderlich: siehe Original-PDF, Seite 10. Grafik nicht in dieser CSV enthalten.] A) The scale at B depicts the value for the angle of attack. B) The curve on this graph depicts a cambered aerofoil. C) D gives the value for the critical angle. D) The scale at A depicts the value of lift. E) The curve on this graph depicts a symmetrical aerofoil. F) C is the point of maximum lift of this graph.

47. On a __________ wing, lift is produced before the wing reaches a positive angle of attack (alpha). A) cambered B) symmetrical

48. Increasing the aerofoil’s camber moves the CL / Alpha line __________. A) upwards. B) downwards. C) horizontally.

49. An aerofoil designed for high speed flight tends to have __________ camber compared to a general purpose low-speed aerofoil. A) less. B) more. C) the same.

50. The critical angle of a thin aerofoil is __________ compared to that for a thick aerofoil. A) smaller. B) larger. C) the same.

51. Which 2 of the following statements are correct? A) The critical angle of attack (alphaCRIT) is the point of CL MAX. B) The critical angle of attack is also known as the stalling angle of attack. C) The aerofoil stalls at the stalling angle of attack. D) Beyond the critical angle no lift is produced.

52. The 3 main factors which affect CL in low subsonic flight are: A) The angle of attack. B) The thickness of the aerofoil section. C) The camber of the aerofoil. D) The speed of the air flow. E) The surface area of the aerofoil. F) The density of the air.

53. A Diamond DA-42 has a wing area of 16.5 square metres. The wing’s coefficient of lift is 0.6. Calculate the lift produced by the wing when the aircraft is flying level at a speed of 120 kt at sea level in ISA conditions. Use 1 kt = 0.514 m/s. A) 23 069 N B) 22 990 kg C) 23 900 N D) 2299 kg

54. A Diamond D-42 is gliding at 80 kt. Its current altitude is 5000 ft where the density today is 0.9 kg/m³. It’s wing area is 16.5m². At glide speed the CD is 0.02. Calculate the drag produced by the wings. A) Approximately 250 newtons B) Approximately 350 newtons C) Approximately 200 newtons D) Approximately 300 newtons

55. In 2D flow, the 2 physical phenomena which create drag are: A) Form drag. B) Skin friction drag. C) Momentum drag. D) Inference drag. E) Induced drag.

56. Which component of the aircraft replaces the energy lost to drag? A) The engine. B) The propeller. C) The lift. D) Gravity.

57. Form drag __________ with increasing angle of attack. A) increases. B) decreases. C) doesn't change.

58. Study this sketch carefully. Identify which 6 of the following statements are correct: A) G is called the wake. B) C is the turbulent boundary layer. C) B is the transition point D) E is the separation point. E) F is a region of reverse flow. F) A is a region of reverse flow. G) D is a region where the flow speed is less than 99% of the free stream flow speed. H) E is the transition point. I) B is the separation point J) A is the turbulent boundary layer.

59. Thin, slippery and low energy, with relatively little drag' is a description of the __________ boundary layer. A) laminar. B) turbulent. C) sonic.

60. A turbulent boundary layer __________ separation. A) delays. B) provokes early. C) has no impact.

61. The position where the kinetic energy of the boundary layer can no longer overcome the adverse pressure gradient is called the __________ __________. A) separation point B) stagnation point C) transition level

62. After the peak suction point the static pressure along the chord __________. A) increases. B) decreases. C) remains constant.

63. Flow reversal occurs __________ of the separation point. A) upstream. B) downstream. C) at position.

64. As alpha __________ the strength of the adverse pressure gradient increases, which causes the separation point to move forward. A) increases B) decreases

65. A turbulent boundary layer is __________ energetic than a laminar boundary layer. A) more. B) less. C) just as.

66. A laminar boundary layer creates __________ drag than a turbulent boundary layer. A) less. B) more. C) the same.

67. The units of wing loading (I) W /S and (II) dynamic pressure q are:

68. The relative thickness of an aerofoil is expressed in:

69. Assuming no flow separation, which of these statements about the flow around an aerofoil as the angle of attack decreases are correct or incorrect? I. The stagnation point moves down. II. The point of lowest static pressure moves forward.

70. A plain flap will increase CLMAX by:

71. Bernoulli's equation can be written as (PT = total pressure, PS = static pressure, q = dynamic pressure):

72. Bernoulli's equation can be written as: (pt = total pressure, ps = static pressure and q = dynamic pressure):

73. What is the SI unit of measurement for power?

74. The stagnation point is the point:

75. Which of these statements about boundary layers is correct?

76. Which boundary layer, when considering its velocity profile perpendicular to the flow, has the greatest change in velocity close to the surface?