**Momentum**

In classical mechanics, **linear momentum** or **translational momentum** (pl. momenta; SI unit kg m/s, or, equivalently, N s) is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter, or moving slower, then it would have less momentum.

Like velocity, linear momentum is a vector quantity, possessing a direction as well as a magnitude:

Linear momentum is also a *conserved* quantity, meaning that if a closed system is not affected by external forces, its total linear momentum cannot change. In classical mechanics, conservation of linear momentum is implied by Newton's laws; but it also holds in special relativity (with a modified formula) and, with appropriate definitions, a (generalized) linear momentum conservation law holds in electrodynamics, quantum mechanics, quantum field theory, and general relativity.

Read more about Momentum: Newtonian Mechanics, Generalized Coordinates, Classical Electromagnetism, Quantum Mechanics, History of The Concept

### Other articles related to "momentum":

... Integrates Interactive Properties into Tribal DDB iMedia Summit interview with Steven Marrs

**Momentum**Entertainment Launches Scripted Division Marketing Agency

**Momentum**Launches Entertainment Company ...

**Momentum**- History of The Concept

... John Philoponus developed a concept of

**momentum**in his commentary to Aristotle's Physics ... This should not be read as a statement of the modern law of

**momentum**, since he had no concept of mass as distinct from weight and size, and more importantly he believed that it is speed rather ... The first correct statement of the law of conservation of

**momentum**was by English mathematician John Wallis in his 1670 work, Mechanica sive De Motu, Tractatus ...

**Momentum**(finance)

... In finance,

**momentum**is the empirically observed tendency for rising asset prices to rise further, and falling prices to keep falling ... The existence of

**momentum**is a market anomaly, which finance theory struggles to explain ... of financial economics have largely attributed the appearance of

**momentum**to cognitive biases, which belong in the realm of behavioral economics ...

**Momentum**

... Legal

**Momentum**, formerly known as NOW Legal Defense and Education Fund, is the oldest legal advocacy group for women in the United States ... Founded in 1970, Legal

**Momentum**is a liberal multi-issue organization dedicated to advancing women’s rights across the country ... In its advocacy role, Legal

**Momentum**maintains a public-access database of current and recent cases in litigation of interest to legal practitioners and people involved in or ...

... related to the Navier–Stokes equations, because the flow of

**momentum**in a fluid is mathematically similar to the flow of mass or energy ... in which case the Navier–Stokes equation is where M is the

**momentum**of the fluid (per unit volume) at each point (equal to the density multiplied by ... the term on the left-hand side describes the change in

**momentum**at a given point the first term on the right describes viscosity, which is really the ...