PHYS 1007 Lecture Notes - Lecture 10: Conical Pendulum, Friction
9 Apr 2016
School
Department
Course
Professor
Document Summary
Moion of planets: kepler"s laws: all planets move in ellipses, a line drawn between planet and sun sweeps out equal areas in equal ime, t2 = (4 2/gms)r3. **force must be parallel to direcion of travel. ** vf2 = vi2 +2a x rearranged a = (vf2-vi2)/(2 x) Deine ( mv2) as kineic energy k. ** this proof only works for situations where acceleraion is constant. Total work & work done by dissipaive forces. If, for example, we are tugging a box across a fricional loor by a string, The work done on the box is +tcos x. The work done against fricion fkcos x *** but since fricion is in opposite direcion, angle is 180 degrees cos180 = -1. Therefore we get: -fk x is the work/energy removed from the mechanical system and is no longer able to move the system (wnc) New work energy theorem for this case no longer just says w= k.
