Working mass Working mass Working mass, also referred to as reaction mass, is a mass against which a system operates in order to produce acceleration. In the case of a rocket, for example, the reaction mass is the fuel shot backwards to provide propulsion. All acceleration requires an exchange of momentum, which can be thought of as the "unit of movement". Momentum is related to mass and velocity, as given by the formula "P = mv," where "P" is the momentum, "m" the mass, and "v" the velocity. The velocity of a body is easily changeable, but in most cases the mass
Tensor product of modules in its right argument: In the general case, each element of the tensor product of modules gives rise to a left "R"-linear map, to a right "R"-linear map, and to an "R"-bilinear form. Unlike the commutative case, in the general case the tensor product is not an "R"-module, and thus does not support scalar multiplication. Both cases hold for general modules, and become isomorphisms if the modules "E" and "F" are restricted to being finitely generated projective modules (in particular free modules of finite ranks). Thus, an element of a tensor product of modules over a ring "R" maps canonically