PHYS112 Lecture Notes - Lecture 6: Equipotential, Potential Energy, Conservative Force

• School: University of Waterloo
• Department: Physics
• Course: PHYS112
• Professor: Carey Bissonnette

Document Summary

Conservative and non-conservative forces: conservative force: a conservative force does zero total work on any closed path. In addition, the work done by a conservative force in going from point a to point b is independent of the path from a to b. (ex. Gravity, springs: nonconservative force: the work done by a nonconservative force on a closed path is nonzero. Friction, air resistance, tension, forces exerted by motors and muscles) Once the choice is made, it must be consistent: gravity: if y=0 is the zero level, u=mgy, spring: choosing x=0, u = kx2. Conservation of mechanical energy: mechanical energy is the sum of the potential and kinetic energies of a system: e = u + Work done by nonconservative forces: change in mechanical energy: the work done by a nonconservative force is equal to the change in mechanical energy of a system: w nc= e=ef e i.