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,
Mass marketing Mass marketing Mass marketing is a market strategy in which a firm decides to ignore market segment differences and appeal the whole market with one offer or one strategy, which supports the idea of broadcasting a message that will reach the largest number of people possible. Traditionally mass marketing has focused on radio, television and newspapers as the media used to reach this broad audience. By reaching the largest audience possible, exposure to the product is maximized, and in theory this would directly correlate with a larger number of sales or buys into the product. Mass marketing is the opposite