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The '''Coriolis force''' is one of three [[fictitious forces]] that act in rotating [[frame of reference|frames of reference]] such as the [[earth]].<ref>[https://www.britannica.com/science/Coriolis-force britannica.com]</ref> It is fictitious in the sense that it does not derive from a physical force such as [[gravity]] or [[electromagnetism]]. While [[Newton's Laws of Motion|Newton's laws of motion]] are strictly only valid in [[inertial frame of reference|inertial]] (non-accelerating) frames of reference, by including fictitious forces such as the Coriolis force as additional forces Newton's second law can be used to describe the motion of objects when viewed from rotating reference frames. A commonly given example of the Coriolis force in action is how [[hurricane]]s in the [[Northern hemisphere]] rotate counterclockwise while cyclones and typhoons in the [[Southern hemisphere]] rotate clockwise.<ref>[http://www.metoffice.gov.uk/learning/learn-about-the-weather/how-weather-works/coriolis-effect metoffice.com]</ref> The other two fictitious forces that exist in rotating frames are the centrifugal and Euler forces.

The '''Coriolis force''' is one of three [[fictitious forces]] that act in rotating [[frame of reference|frames of reference]] such as the [[earth]].<ref name=britannica>[https://www.britannica.com/science/Coriolis-force britannica.com]</ref> It is the cause of the perceived bend in the flight path of airborne objects.<ref>Wile, Dr. Jay L. ''Exploring Creation With Physical Science''. Apologia Educational Ministries, Inc. 1999, 2000</ref> This is known as a fictitious becase it is not derived from a physical force such as [[gravity]] or [[electromagnetism]]. While [[Newton's Laws of Motion|Newton's laws of motion]] are strictly only valid in [[inertial frame of reference|inertial]] (non-accelerating) frames of reference, by including fictitious forces such as the Coriolis force as additional forces Newton's second law can be used to describe the motion of objects when viewed from rotating reference frames. A commonly given example of the Coriolis force in action is how [[hurricane]]s in the [[Northern hemisphere]] rotate counterclockwise while cyclones and typhoons in the [[Southern hemisphere]] rotate clockwise.<ref>[http://www.metoffice.gov.uk/learning/learn-about-the-weather/how-weather-works/coriolis-effect metoffice.com]</ref> The other two fictitious forces that exist in rotating frames are the centrifugal and Euler forces.<br />

==Mathematics==

==Mathematics==

The [[acceleration]] of an object due to the Coriolis force, a_c can be described mathematically by:

[[File:Coriolis effect10.svg.png|thumb|right|200px|Hurricane formation in the Northern hemisphere: the Coriolis force (red) causes deflection of air currents. Blue arrows represent the pressure gradient force.]]The Coriolis force acting on a mass m, can be described mathematically by:

<math>

:<math>

\vec{a_c} = -2 \vec{\omega} \times \vec{v}

\vec{F} = -2 m \vec{\omega} \times \vec{v}

</math>

</math>

where ω is the angular velocity of the rotating reference frame and v is the [[velocity]] of the object when viewed from an [[inertial frame of reference]] (non-accelerating). The [[cross product]] means that the Coriolis force acts at right angles to both the velocity of the object and angular velocity of the reference frame.

where ω is the angular velocity of the rotating reference frame and v is the [[velocity]] of the object when viewed from an [[inertial frame of reference]] (non-accelerating). The [[cross product]] means that the Coriolis force acts at right angles to both the velocity of the object and angular velocity of the reference frame.

This can be used to explain the rotation directions of [[hurricane]]s, cyclones and typhoons. On earth, the angular velocity [[vector]] points up out of the North pole. Supposing the wind is blowing from the South in the Northern hemisphere, the Coriolis force will act to bend it to the right when viewed from above. This means tropical storms in the Northern hemisphere (hurricanes) will rotate counterclockwise. Similarly in the Southern hemisphere and air current travelling South will be bent to the right and so cyclones and typhoons in the Southern hemisphere will rotate clockwise. The deflection of something by the Coriolis force is known as the [[Coriolis effect]].

This can be used to explain the rotation directions of [[hurricane]]s, cyclones and typhoons. On earth, the angular velocity [[vector]] points up out of the North pole. Supposing the wind is blowing from the South in the Northern hemisphere, the Coriolis force will act to bend it to the right when viewed from above. This means tropical storms in the Northern hemisphere (hurricanes) will rotate counterclockwise. Similarly in the Southern hemisphere and air current travelling South will be bent to the left and so cyclones and typhoons in the Southern hemisphere will rotate clockwise. The deflection of something by the Coriolis force is known as the Coriolis effect.

==References==

==References==

==See Also==

==See also==

[[Coriolis effect]]

*[[Fictitious forces]]

*[[Euler force]]

[[Category:Physics]]

[[Category:Physics]]

[[Category:Mechanics]]

[[Category:Mechanics]]