Sound   Introduction   Longitudinal waves with regions of high and low pressure that travel through a medium   Audible, Infrasonic, Ultrasonic   Speed of sound varies with temperature and density of the medium 343 m/s at 23°C in air 6/4/2016APHY1011

Sound   Sound Waves   Regions of condensation and rarefaction Example   The particles experience simple harmonic motion as the wave passes them Remember that the particles are already moving when the wave reaches them. 6/4/2016APHY1012

Sound   Doppler Effect   Apparent change in the frequency of the wave due to motion of the source or observer Sound (trains, sirens) and light 6/4/2016APHY1013

Sound   Supersonic Speed and Shock Waves   Shockwave and Mach cone 6/4/2016APHY1014

Wave Superposition and Interference   Superposition   Adding the displacements of two or more waves that are interacting. Constructive and destructive 6/4/2016APHY1015

Wave Superposition and Interference   Standing Waves   Adding of two identical waves moving in opposite directions Simulation   Nodes and Antinodes   String and wind instruments 6/4/2016APHY1016

Wave Superposition and Interference   Harmonics 6/4/2016APHY1017

Wave Superposition and Interference   Harmonics 6/4/2016APHY1018

Wave Superposition and Interference   Beats   Interference of two sounds with different frequencies Tuning instruments in an orchestra 6/4/2016APHY1019