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14.2 Definitions, Terminology, Units and Abbreviations

14.2.2 State the International System (SI) and ICAO units used to express:

(a) distance;

metre (m)

(b) time;

second (s)

(c) velocity;

nautical miles/hour (kts)

(d) mass;

kilogram (kg)

(e) volume;

cubic metre (m³)

(f) temperature;

degrees Celsius (ºC)

(g) altitude.

feet (ft)


14.2.4  Define and where appropriate show the relevant relationships between:

(a) mass, weight and gravitational force (g);

Mass (m)

  • the amount of matter in an object. 
  • 1kg of mass on the earth is the same as 1kg of mass on the moon.


  • the force produced by gravitational attraction between masses.
  • Weight = mass x gravity
  • the 1kg of mass is heavier on the earth than on the moon.

Gravitational Force

  • a force acting towards the centre of an object.
  • the bigger the object, the bigger the force.

(b) inertia;

  • A property of matter by which it continues in its existing state of rest or uniform motion in a straight line.
  • More mass = more inertia.
  • Newton's first law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force.
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