Conceptual

Force Defined by Negative Gradient of Potential Energy in Classical Mechanics

The core principle establishes that conservative forces in classical mechanics act as the negative gradient of their corresponding potential energy scalar field. This relationship is formally defined through the equation $\mathbf{F} = -\nabla U$, where a force vector pointing toward decreasing potential energy drives the system's configuration changes within a conservative field. The concept resides strictly within Lagrangian and Hamiltonian mechanics, serving as a foundational postulate for deriving equations of motion via variational principles without explicit reference to mass or time-dependent parameters in the definition itself.