13.1 Types of Waves - Physics | OpenStax

Learning Objectives

• Define mechanical waves and medium, and relate the two.
• Distinguish a pulse wave from a periodic wave.
• Distinguish a longitudinal wave from a transverse wave and give examples.

Key Terms

• Longitudinal Wave
• Mechanical Wave
• Medium
• Wave
• Periodic Wave
• Pulse Wave
• Transverse Wave

Mechanical Waves

• Waves are disturbances that propagate from their point of origin.
• They transfer energy without transferring mass.
• Examples: light, sound, and ocean waves.
• Sound and Water Waves: Mechanical waves requiring a medium (solid, liquid, or gas) to travel.
• Light: Not a mechanical wave; can travel through a vacuum.
• Waves have common characteristics: amplitude, period, frequency, and energy.

Misconception Alert

• Water waves don't push water in one direction; particles move up and down, not horizontally.

Types of Waves

Pulse Waves vs. Periodic Waves

• Pulse Wave: A sudden disturbance, creating one or few waves (e.g., pebble in water, thunder).
• Periodic Wave: Repeats oscillations consistently, often linked with harmonic motion.

Longitudinal Waves vs. Transverse Waves

• Transverse Waves
  • Disturbance is perpendicular to the direction of propagation.
  • Example: Toy spring moved up and down creates horizontal waves (Figure 13.3).
• Longitudinal Waves
  • Disturbance is parallel to the direction of propagation.
  • Example: Toy spring stretched and compressed horizontally creates horizontal waves (Figure 13.4).

Combination Waves

• Waves can also be a combination of transverse and longitudinal.
• Example: Surface waves in earthquakes.
• Sound Waves in air/water are typically longitudinal, but in solids, they can be both.

The Physics of Surfing

• Waves grow due to wind energy transfer; stronger winds create higher waves.
• Ocean waves are more complex than simple transverse waves.
• Orbital Progressive Waves: Particles move in a circular path from crest to trough.
• Shoaling: Waves increase in height as they approach shallower waters.

Conclusion

• Understanding wave types is crucial for comprehending wave behavior in different media.
• Waves in various forms have significant applications in physics and real-world scenarios like surfing and earthquakes.