Mechanical Waves

📋 Course Outline

1. Wave Propagation and Wavelength
2. Wavefronts and Wave Types
3. Source and Point Equations
4. Phase and Spatial Profiles
5. Phase Difference and Stroboscopy

📖 1. Wave Propagation and Wavelength

🔑 Key Concepts & Definitions

• Progressive wave : a phenomenon resulting from the propagation of a series of identical disturbances emitted regularly by a source
• Wavelength : the distance traveled by a wave during one temporal period $T$, and it depends on the propagating medium

★ Must-know

📐 Formula — The wavelength satisfies $\lambda = T V = \frac{V}{N}$, where $V$ is the wave speed and $N$ is the frequency.

Further detail

• Two consecutive water ridges of the same nature, both crests or both troughs, are separated by one wavelength $\lambda$.

💡 Memory Hook

Repeated source disturbances → progressive wave propagation

📖 2. Wavefronts and Wave Types

🔑 Key Concepts & Definitions

• Wavefront : the most advanced disturbance created by the source

📌 The wavefront is a crest when the source motion begins upward, with source phase $\varphi_S=0$, and a trough when the source motion begins downward, with source phase $\varphi_S=\pi$.