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🫴Physical Science Unit 11 Review

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11.1 Properties and Types of Waves

🫴Physical Science
Unit 11 Review

11.1 Properties and Types of Waves

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
🫴Physical Science
Unit & Topic Study Guides

Waves are fundamental to understanding how energy moves through space and matter. From ripples in a pond to light beams, waves shape our world. This section dives into wave properties, types, and math, laying the groundwork for grasping sound and other wave phenomena.

We'll explore wavelength, amplitude, and frequency, and how they relate. We'll also look at different wave types, like transverse and longitudinal, and how they behave in various media. This knowledge is key to understanding the chapter's broader themes.

Wave Properties

Fundamental Wave Characteristics

  • Wavelength measures the distance between two consecutive crests or troughs in a wave
  • Amplitude represents the maximum displacement of a wave from its equilibrium position
  • Frequency indicates the number of complete wave cycles passing a fixed point per second
  • Period calculates the time required for one complete wave cycle to occur
  • Wave speed determines how quickly a wave travels through a medium

Wave Structure Components

  • Crest forms the highest point of a transverse wave above the equilibrium position
  • Trough creates the lowest point of a transverse wave below the equilibrium position
  • Nodes occur at points where a wave has zero displacement from its rest position
  • Antinodes represent locations of maximum displacement in a standing wave

Relationships Between Wave Properties

  • Wavelength and frequency exhibit an inverse relationship (as one increases, the other decreases)
  • Period inversely relates to frequency (T = 1/f, where T is period and f is frequency)
  • Wave speed depends on both wavelength and frequency (v = λf, where v is speed, λ is wavelength, and f is frequency)
  • Amplitude affects the energy carried by a wave (higher amplitude means more energy)

Types of Waves

Classification by Vibration Direction

  • Transverse waves oscillate perpendicular to the direction of wave propagation
    • Particles move up and down while the wave moves horizontally
    • Commonly observed in water waves and electromagnetic waves
  • Longitudinal waves vibrate parallel to the direction of wave propagation
    • Particles compress and expand along the same axis as wave movement
    • Sound waves in air exemplify longitudinal waves

Classification by Medium Requirements

  • Mechanical waves require a physical medium to propagate
    • Transfer energy through matter (solids, liquids, or gases)
    • Include water waves, sound waves, and seismic waves
  • Electromagnetic waves travel through vacuum or matter
    • Do not require a physical medium for propagation
    • Consist of electric and magnetic field oscillations
    • Encompass light, radio waves, X-rays, and gamma rays

Wave Behavior in Different Media

  • Reflection occurs when waves bounce off a boundary between two media
  • Refraction happens as waves change direction when entering a new medium
  • Diffraction involves waves bending around obstacles or spreading through openings
  • Interference results from the combination of two or more waves in the same space

Wave Mathematics

Wave Equation and Its Applications

  • Wave equation relates wave speed, frequency, and wavelength: v = fλ
  • Rearranging the equation allows calculation of unknown variables (f = v/λ or λ = v/f)
  • Applies to all types of waves, including mechanical and electromagnetic

Frequency and Period Calculations

  • Frequency (f) and period (T) relate through the equation: f = 1/T
  • Used to determine oscillation rate or time for one complete cycle
  • Essential for analyzing wave behavior in various applications (music, communications)

Energy and Intensity Relationships

  • Wave energy proportional to the square of the amplitude
  • Intensity of a wave decreases with distance from the source (inverse square law)
  • Calculations involve considering wave speed, frequency, and medium properties