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,
Power (physics) yields: where "A" and "B" are the beginning and end of the path along which the work was done. The power at any point along the curve "C" is the time derivative In one dimension, this can be simplified to: In rotational systems, power is the product of the torque τ and angular velocity ω, where ω measured in radians per second. The formula_13 represents scalar product. In fluid power systems such as hydraulic actuators, power is given by where "p" is pressure in pascals, or N/m and "Q" is volumetric flow rate in m/s in SI units. If a