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
Escape velocity a body that falls under the force of gravitational attraction of mass "M", from infinity, starting with zero velocity, will strike the massive object with a velocity equal to its escape velocity given by the same formula. When given an initial speed formula_2 greater than the escape speed formula_3 the object will asymptotically approach the "hyperbolic excess speed" formula_4 satisfying the equation: In these equations atmospheric friction (air drag) is not taken into account. A rocket moving out of a gravity well does not actually need to attain escape velocity to escape, but could achieve the same result (escape) at