Wave | Behavior, Definition, & Types

Introduction to Waves

• Waves are disturbances that propagate through a medium or space.
• Common examples include water waves, sound waves, light waves, and subatomic particle motion.
• Waves exhibit periodic motion, having a fixed frequency and wavelength.
• Mechanical waves (e.g., sound) require a medium, while electromagnetic waves (e.g., light) do not.

Types and Features of Waves

• Transverse Waves: Oscillations are perpendicular to the wave direction (e.g., water waves).
• Longitudinal Waves: Oscillations occur in the direction of the wave (e.g., sound waves).
• Key characteristics:
  • Crest: Highest point of a transverse wave.
  • Trough: Lowest point of a transverse wave.
  • Compression: High-pressure region in a longitudinal wave.
  • Rarefaction: Low-pressure region in a longitudinal wave.
• Wave properties:
  • Wavelength: Distance between successive crests/troughs.
  • Amplitude: Height of the wave.
  • Frequency: Number of crests/troughs passing a point per unit time.
  • Velocity: Product of wavelength and frequency.

Wave Behavior

• Waves exhibit several phenomena:
  • Reflection: Waves bounce back after hitting a barrier.
  • Refraction: Bending of waves as they enter a medium with different speed properties.
  • Diffraction: Bending and spreading out of waves around obstacles or through openings.
  • Interference: Waves overlap, creating constructive (amplified) or destructive (diminished) interference.
  • Doppler Effect: Change in frequency as the wave source moves relative to the observer.

Detailed Wave Behaviors

• Reflection: Angle of incidence equals angle of reflection.
• Refraction: Governed by the speed of waves in different media; Snell's law applies to light.
• Diffraction: Occurs when wave encounters obstacles/openings smaller than its wavelength.
• Interference: Depends on phase alignment; can result in reinforcement or cancellation of waves.
• Doppler Effect: Observed as a frequency change, such as pitch change in sound or red/blue shift in light.

Standing Waves

• Occur when waves are confined within boundaries, causing reflection and interference.
• Characterized by nodes (no displacement) and antinodes (maximum displacement).
• Frequencies are determined by boundary conditions, leading to harmonics or overtones.