Changes

For example, when an airplane is taking off, the air under the wings is exerting a force in an upward direction, gravity is exerting a force in a downward direction, the engine is exerting a force pushing the plane forward, while winds may be exerting forces from side to side.  

For example, when an airplane is taking off, the air under the wings is exerting a force in an upward direction, gravity is exerting a force in a downward direction, the engine is exerting a force pushing the plane forward, while winds may be exerting forces from side to side.  

Temperature is an example of a scalar quantity. The temperature is simply a number of units: normal body temperature is 37° Celsius. You can't speak of an upward temperature, or a northeast temperature; it has no direction.

Temperature is an example of a scalar quantity. The temperature is simply a number of units: normal body temperature is 37° Celsius. You can't speak of an upward temperature, or a northeast temperature; it has no direction. The temperature [[trend]] however does have a direction ([[up]] or [[down]]).

==References==

==References==