Mass in special relativity (including the kinetic energy of the gas) only when it is measured in the center of momentum frame. Just as is the case for single particles, the calculated "rest mass" of such a container of gas does not change when it is in motion, although its "relativistic mass" does change. The container may even be subjected to a force which gives it an overall velocity, or else (equivalently) it may be viewed from an inertial frame in which it has an overall velocity (that is, technically, a frame in which its center of mass has a velocity). In this case,
Detonation velocity detonation velocity of the explosive is calculated and is expressed in km/s. Detonation velocity Explosive velocity, also known as detonation velocity or velocity of detonation (VoD), is the velocity at which the shock wave front travels through a detonated explosive. The data listed for a specific substance is usually a rough prediction based upon gas behavior theory (see Chapman-Jouguet condition), as in practice it is difficult to measure. Explosive velocities are always faster than the local speed of sound in the material. If the explosive is confined before detonation, such as in an artillery shell, the force produced is focused