PHYS 101 Lecture Notes - Lecture 29: Angular Frequency, Propagation Constant, Simple Harmonic Motion

• School: Simon Fraser University
• Department: Physics
• Course: PHYS 101
• Professor: Andrew Debenedictis

Document Summary

Phys 101: physics for the life sciences lecture 29: Take as the system the spring and the mass. There is no friction, therefore friction does no work on the system. The weight and normal force are perpendicular to the direction of displacement and therefore they also do not work on the system. Since there are no external forces acting on the system the mechanical energy is conserved. 2 m k a2[si n2( t+ )+cos2( t + )] (recall: si n2 +co s2 =1 ) Plot of ke and pe vs time (at t=0 the spring is fully stretched) We can also plot ke and pe vs x. Pe= the potential energy in the spring 1. 2 (we need to write this in terms of x) mv 2 k x2 k a2. 1 mv 2+ 1 k x2=1 k a 2. What we have talked about so far are undamped oscillators (simple harmonic motion -