4.4 Waves

Key Concepts

• Waves: Disturbances that transfer energy from one point to another without the transfer of matter.
• Types of Waves:
  • Transverse Waves: Oscillations are perpendicular to the direction of wave travel (e.g., electromagnetic waves).
  • Longitudinal Waves: Oscillations are parallel to the direction of wave travel (e.g., sound waves).

Wave Properties

• Wavelength (λ): Distance between two consecutive points in phase on the wave (e.g., crest to crest).

• Frequency (f): Number of oscillations per unit time, measured in Hertz (Hz).

• Amplitude: Maximum displacement of a point on the wave from its equilibrium position.

• Speed (v): The rate at which the wave propagates through a medium, calculated by the formula:

  [ v = f \times λ ]

Wave Equations

• Wave Equation: Describes the relationship between wave speed, frequency, and wavelength.

Wave Phenomena

• Reflection: Bouncing back of a wave when it hits a barrier.
• Refraction: Bending of a wave as it passes from one medium to another due to a change in speed.
• Diffraction: Spreading out of waves when they pass through a narrow aperture or around an obstacle.
• Interference: When two waves overlap, they can interfere constructively (amplitude increases) or destructively (amplitude decreases).

Applications

• Understanding wave behavior is crucial in fields like optics, acoustics, and telecommunications.

Summary

Waves are essential concepts in physics that describe how energy is transmitted through different media. By studying their properties and behaviors such as reflection, refraction, and diffraction, we can better understand a wide array of natural and technological phenomena.