Lecture
This lecture covers the concept of principal stresses and axes, spectral decomposition, simple states of stress like hydrostatic and deviatoric stress, and equilibrium equations in continuum mechanics. It also explains the Cauchy stress tensor symmetry and the physical necessity of a symmetric stress tensor. The instructor emphasizes the importance of the balance of linear and angular momentum for a body, as well as the fundamental equation of motion in continuum mechanics. The lecture concludes with a discussion on Newton's Law for static problems.