Single-Particle Electrodynamics - Assassination Science

most appropriate in the task of removing some of the confusion that often
surrounds the concepts involved.
2.3.1 Mechanical momentum
Today, we refer to Newton’s “quantity of motion”, p, by the term mechanical
momentum. In what may at first appear to be pedantry, the author will never
delete the adjective “mechanical” from the term “mechanical momentum”, in
this thesis; and, furthermore, the author will always use the symbol p for the
mechanical momentum, and will not use this symbol for any other quantity.
The reason for the author’s insistence on this point will be manifestly
clear by the end of Chapter 4.
If one trades-in Galilean mechanics in favour of Einsteinian mechanics
(to be discussed in more detail shortly), the definition of the mechanical
momentum is simply upgraded:
p ≡ mγv,
where every appearance of a velocity v implies the definition of a corresponding
gamma factor,
γ ≡
1
√
1 − v
2 ,
and where our choice of units is described in Section A.3.4.
2.3.2 Mechanical energy
Of a supplementary but useful rôle in Newtonian physics is the mechanical
energy of a particle, which, in Galilean mechanics, is given by
W ≡ 1 2 mv2 . (2.2)
Again, the author shall always refer to the quantity (2.2) using the adjective
mechanical, and shall always use the symbol W .
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