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In Newtonian mechanics, momentum (pl.: 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 directi
The population momentum is calculated by dividing this final total population number by the starting population. [4] Momentum, Ω, can be expressed as: = In this equation, b is the crude birth rate while e o is the life expectancy at birth. Q is the total number of births per initial birth.
The moment of force, or torque, is a first moment: =, or, more generally, .; Similarly, angular momentum is the 1st moment of momentum: =.Momentum itself is not a moment.; The electric dipole moment is also a 1st moment: = for two opposite point charges or () for a distributed charge with charge density ().
Newton's laws are often stated in terms of point or particle masses, that is, bodies whose volume is negligible. This is a reasonable approximation for real bodies when the motion of internal parts can be neglected, and when the separation between bodies is much larger than the size of each.
Momentum: the drag experienced by a rain drop as it falls in the atmosphere is an example of momentum diffusion (the rain drop loses momentum to the surrounding air through viscous stresses and decelerates). The molecular transfer equations of Newton's law for fluid momentum, Fourier's law for heat, and Fick's law for mass are
This definition has been championed by Ernst Mach [25] [26] and has since been developed into the notion of operationalism by Percy W. Bridgman. [27] [28] The simple classical mechanics definition of mass differs slightly from the definition in the theory of special relativity, but the essential meaning is the same.
The definition of angular momentum for a single point particle is: = where p is the particle's linear momentum and r is the position vector from the origin. The time-derivative of this is: The time-derivative of this is:
In this definition, there is a critical pressure and an associated critical density, and when nuclear matter (made of protons and neutrons) is compressed beyond this density, the protons and neutrons dissociate into quarks, yielding quark matter (probably strange matter). The narrower meaning is quark matter that is more stable than nuclear matter.