Virial

nounStandard termMechanical

A scalar quantity used in mechanics to relate the kinetic energy of a system to the forces acting on its particles.

In statistical mechanics and dynamics, the virial is defined as half the sum of the dot product of the forces on particles and their position vectors. The virial theorem states that for a stable, bound system, the time-averaged kinetic energy equals the virial of the forces. It provides a macroscopic way to analyze complex multi-particle systems like gases under pressure without tracking individual particle trajectories.

Heard on the job

We can apply the virial theorem to estimate the average kinetic energy of the gas particles in the cylinder based on the boundary forces.