Mass in special relativity the mass of a moving particle." When the relative velocity is zero, formula_33 is simply equal to 1, and the relativistic mass is reduced to the rest mass as one can see in the next two equations below. As the velocity increases toward the speed of light "c", the denominator of the right side approaches zero, and consequently formula_33 approaches infinity. In the formula for momentum the mass that occurs is the relativistic mass. In other words, the relativistic mass is the proportionality constant between the velocity and the momentum. While Newton's second law remains valid in the form the
Thermal velocity Boltzmann constant, formula_2 is the temperature, and formula_3 is the mass of a particle, then we can write the different thermal velocities: If formula_4 is defined as the root mean square of the velocity in any one dimension (i.e. any single direction), then If formula_4 is defined as the mean of the magnitude of the velocity in any one dimension (i.e. any single direction), then If formula_4 is defined as the most probable speed, then If formula_4 is defined as the root mean square of the total velocity (in three dimensions), then If formula_4 is defined as the mean of