## Useful Gibberish

### Calculate kinetic energy in YADE

The term kinetic energy $E_{c}$ when modelling in DEM is needed to define which state the simulation is in: quasi-static or dynamic.

For a quasi-static system, we have $E_{c} < 10^{-7}$ and for dynamic system we’ll have $E_{c}>10^{-7}$ (J).

$E_{c}$ is calculated by the formula: $\sum {\frac{1}{2}} ( {m_{i}}{v_{i}}^{2}+\omega ( I{{\omega }^{T}} ) )$

Where:

$m_{i}$: density of the particle i

$v_{i}$: velocity of particles

$I$: inertia tensor