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Definition of momentum\

It is convenient to define a physical quantity called momentum, usually indicated by the symbol , as the product of its mass by its velocity

(1)

The momentum is a vector quantity which has the same direction as the velocity of a body.

The unit of measurement of momentum in the SI system is the product of the units of mass and velocity and thus is the kg m/s.

A new form of the Second Newton’s Law\

Newton’s Second Law can be expressed in terms of change in momentum:

(2)

which can be written in the more compact form

(3)

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