Conceptual

Classical Mechanics | Lecture 2

Classical mechanics posits that physical systems evolve deterministically through phase space, where state is defined by position and momentum (or velocity), governed by Newton's laws within inertial reference frames. Theoretical principles dictate that forces in conservative fields are derived from a scalar potential energy function ($F = -\nabla V$), leading to the fundamental conservation of total mechanical energy ($E = T + V$) and, via action-reaction symmetry, the conservation of linear momentum for closed systems. These laws establish reversible dynamics where time-signature invariance ensures that future trajectories are uniquely determined by initial conditions, distinguishing valid physical theories from irreversible empirical observations like Aristotelian motion dominated by friction.