Velocity quantity, momentum, is a vector and defined by In special relativity, the dimensionless Lorentz factor appears frequently, and is given by where γ is the Lorentz factor and "c" is the speed of light. Escape velocity is the minimum speed a ballistic object needs to escape from a massive body such as Earth. It represents the kinetic energy that, when added to the object's gravitational potential energy, (which is always negative) is equal to zero. The general formula for the escape velocity of an object at a distance "r" from the center of a planet with mass "M" is where
Molar mass the number of atoms in each molecule: The molar mass of a compound is given by the sum of the standard atomic weight (namely, the standard relative atomic mass) of the atoms which form the compound multiplied by the molar mass constant, "M": An average molar mass may be defined for mixtures of compounds. This is particularly important in polymer science, where different polymer molecules may contain different numbers of monomer units (non-uniform polymers). The average molar mass of mixtures formula_1 can be calculated from the mole fractions formula_2 of the components and their molar masses formula_3: It can also