PHYS 17200 Lecture Notes - Lecture 6: Modulus Guitars, Friction, Proper Length
25 Mar 2015
School
Department
Course
Professor
Document Summary
Phys 17200 - modern mechanics - lecture 6_ball-spring model of solids. Contact interactions and a model of solid materials. An atom is a neutral system consisting of a positively charged nucleus and a negatively charged cloud of electrons that surrounds it. Typically, the spherical cloud has a radius of about 10^-10 m, the size of the atom. When a little further apart than that they attract each other. When a little closer than that they repel each other. For small changes in their length chemical bonds act like springs! Strain = delta_l / l = change in length / rest length. Stress = f_spring / a = force exerted on wire / cross-sectional area of wire. K_s_wire = (a / l) * y = spring stiffness constant. K_s_bond = stiffness of bond between each atom.
