## Definitions

**Air Speed**: the speed of the plane in the air

**Altitude: **flying height of a plane above sea level

**Compass Rose: **see diagram

**Distance: **the separation between two points, a scalar quantity

**Displacement: **change in position, a vector quantity

**Force: **agent that results in accelerating or deforming an object

**Frame of reference:** coordinate system used to define motion

**Ground Speed: **the resultant vector speed combining air speed and wind speed

**Position:** separation between an object and its reference point

**Reference point:** zero location in a coordinate system

**Resultant: **a vector representing the sum of two or more vectors

**Scalar: **quantity, like distance that has only magnitude

**Speed: **ratio of distance traveled to time interval

**Vector: **quantity having both magnitude and direction

**Velocity:** ratio of change of position to time interval over which change takes place

**Wind barbs:** graphical representations of both the direction and speed of wind