120 Classical Mechanics
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scalar function: the Lagrangian. It is true that when dealing with simple systems the directional
properties of the vectors involved assist our intuition in setting up the problem, but the Lagrangian
method is simpler mathematically as the mechanical system becomes more complex.
Second, the Lagrangian method concentrates solely on active forces, completely ignoring
all internal force effects resulting from joints, connectors, and contact with constraints, and
the Newtonian approach must take the forces of constraint into consideration. So long as con-
straint forces per se are not a consideration, the Lagrangian method offers an advantage that
becomes increasingly attractive as the me ...