Lecture
This lecture covers the propagation of sinusoidal plane waves, wave packets, and the Doppler effect for mechanical and electromagnetic waves. It explains concepts such as phase velocity, group speed, and the sensitivity of the human ear to sound waves. The instructor also discusses the Doppler effect in various scenarios, including when the source and observer are in relative motion. Additionally, the lecture delves into Hubble's law and the redshift of emission lines from distant galaxies, providing insights into the expansion of the universe.