Momentum

In Newtonian mechanics, momentum (: momenta or momentums; more specifically linear momentum or translational momentum) is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction. If is an object's mass and is its velocity (also a vector quantity), then the object's momentum (from Latin pellere "push, drive") is: \mathbf{p} = m \mathbf{v}. In the International System of Units (SI), the unit of measurement of momentum is the kilogram metre per second (kg⋅m/s), which is dimensionally equivalent to the newton-second.

In special relativity, four-momentum (also called momentum–energy or momenergy) is the generalization of the classical three-dimensional momentum to four-dimensional spacetime. Momentum is a vector in three dimensions; similarly four-momentum is a four-vector in spacetime. The contravariant four-momentum of a particle with relativistic energy and three-momentum , where is the particle's three-velocity and the Lorentz factor, is p = \left(p^0 , p^1 , p^2 , p^3\right) = \left(\frac E c , p_x , p_y , p_z\right).

equation

frame of reference

momentum-like vector describing motion of electrons in crystals; conserved up-to a discrete symmetry

physical spaces representing position and momentum, Fourier transform duals

mathematical model in fluid dynamics

Tests of special relativity

relativistic equation relating total energy to invariant mass and momentum

amount of momentum that one particle gives to another particle