Energy & Wave

Units of energy in the SI system:

• • Joule: 1 newton metre

  • Calorie:  to raise the temperature of one gram of water by one degree Celsius at a pressure of one atmosphere

Types of energy: Kinetic, Potential

Thermal energy

• Thermodynamics: Laws of thermodynamics 

• Temperature: Microscopic kinetic energy

• Heat: Heat transfer: Conduction (熱傳導, Wiki) or diffusion (扩散); Convection (熱對流); Radiation (熱輻射, EM radiation)

• Combustion (fire): Heat conduction in metal: UCambridge; Internal combustion engine: Wiki,

Chemical energy

• •  KE vs PE: KE: translations, rotations, vibrations (Wiki); PE: electron bonds

  •  Gibbs free energy: ΔfG = ΔfG˚ + RT ln Qf

  • Internal energy: 

    • • Molecular dynamics; Thermodynamic temp

      • Mol motions: Translation, Vibration, Rotation

      • Videos: Internal energy of gas, Invisible motion of still objects; Inter-molecular PE; Vibration of molecules

Electric energy: Battery, Electric generators

 Basics of Wave 

• Huygens–Fresnel principle/惠更斯－菲涅耳原理(子波,包络面,波面,波线): 反射, 折射, 海浪; Fermat principle/費馬原理; Pitch to frequency

Types

• • Media: Mechanical: Water, sound, seismic; Electromagnetic: light, radio, microwave

  • Vibration: Transverse: EM; Longitudinal: sound (Eureka); Surface/ground: water

Videos

• PSU Russel DA demo

• Boundary behaviors: Free- or fixed-end wave reflection; Wave refraction; PSU (hi to low, low to hi)

• Sound: Showtime

Sound

Standing waves

• James Dann, Arbor Scientific, On Chladni plates; Standing Waves and Resonance, Resonance

Matter wave

• de Broglie wavelength