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PHYS 17200 - Modern Mechanics - Lecture 1_Matter and Interactions
● uses a few fundamental concepts and principles that apply to all kinds of matter
and their interactions
● uses approximations to create simple models able to predict and explain an
enormous range of physical phenomena
● unites mechanical and thermal physics by creating models of ordinary objects as
systems of interacting atoms
● uses powerful computers and computer graphics to simulate and display the
behavior of realistic physical systems
● So, a vector is represented by the triple of its components r_vector= <x, y, z>
which in the case of a position vector are just the position’s three coordinates.
● A position vector’s length is one specific example of the magnitude of a vector
magnitude of r = r_mag= sqrt(x^2+y^2+z^2)
● Multiplying all of a vector’s components by the same scalar factor produces a
vector parallel to the original one but with magnitude larger or smaller by the
● If the scalar factor is negative, the new vector actually points in the direction
opposite the original.
● Specifically, multiplying any vector by the inverse of its magnitude produces a
dimensionless vector parallel to the original
i.e. r_vector/r_mag = r_unitvector