# Formula Coriolis force (+ direction) Angular velocity    Velocity    Mass ## Coriolis force

Unit
Coriolis force is a fictitious force acting on a moving body only in rotating reference systems (such as on the Earth). Coriolis force is always orthogonal to the angular velocity $$\boldsymbol{\omega}$$ of the Earth and the velocity $$\boldsymbol{v}$$ of the body under consideration, for example an airplane flying north. You can use the Coriolis force formula to understand, for example, why clouds in the northern hemisphere move in a spiral.

If the cross product '$$\times$$' is written out, then the three components of the Coriolis force are:$\boldsymbol{F}_{\text c} ~=~ 2m \, \begin{bmatrix} v_y \, \omega_z ~-~ v_z \, \omega_y \\ v_z \, \omega_x ~-~ v_x \, \omega_z \\ v_x \, \omega_y ~-~ v_y \, \omega_x \end{bmatrix}$

## Angular velocity

Unit
Angular velocity indicates the number of rotations per second. For example, the angular velocity of the Earth in units of $$2 \pi$$: $\omega ~=~ \frac{2\pi}{24 \, \text{h}} ~=~ 7.27 \cdot 10^{-5} \, \frac{1}{\text s}$

Angular velocity is a vector with three components:$\boldsymbol{\omega} ~=~ \begin{bmatrix} \omega_x \\ \omega_y \\ \omega_z \end{bmatrix}$

## Velocity

Unit
Velocity of a body, relative to the rotating reference frame. Velocity is a vector with three components:$\boldsymbol{v} ~=~ \begin{bmatrix} v_x \\ v_y \\ v_z \end{bmatrix}$

## Mass

Unit
Mass of the moving body moving with velocity $$\boldsymbol{v}$$ in the rotating reference frame.