Spacetime as a redshift and analyze the effect in terms of scenarios (b) or (d). In classical mechanics, the state of motion of a particle is characterized by its mass and its velocity. Linear momentum, the product of a particle's mass and velocity, is a vector quantity, possessing the same direction as the velocity: p = "mv". It is a "conserved" quantity, meaning that if a closed system is not affected by external forces, its total linear momentum cannot change. In relativistic mechanics, the momentum vector is extended to four dimensions. Added to the momentum vector is a time component that
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