Progressive Waves | Cambridge (CIE) AS Physics Revision Notes 2023

Wave Motion

• Progressive Waves:
  • Transfer energy without transferring matter
  • Move through a medium or vacuum
  • Opposed to standing waves, which do not transfer energy and have fixed nodes/antinodes
  • Energy transferred through oscillations or vibrations (e.g., ropes, springs)

Types of Waves

• Transverse Waves: Oscillations perpendicular to direction of wave travel
• Longitudinal Waves: Oscillations parallel to direction of wave travel

Ripple Tanks

• Demonstrate wave properties: reflection, refraction, diffraction
• Paddle produces a combination of transverse and longitudinal waves

General Wave Properties

• Displacement (x): Distance from equilibrium, vector quantity (positive/negative)
• Amplitude (A): Maximum displacement from equilibrium
• Wavelength (λ): Distance between points on successive oscillations in phase
• Period (T): Time for one complete oscillation/cycle
• Frequency (f): Number of complete oscillations per unit time (Hz)
• Speed (v): Distance traveled by wave per unit time (m/s)

Phase Difference

• Indicates how much a point or wave is ahead/behind another
• In phase: Crests/troughs aligned
• Antiphase: Crest of one aligns with trough of another
• Measured in fractions of wavelength, degrees, or radians

Worked Example

• Amplitude: Maximum displacement
• Wavelength: Distance between identical points
• Phase difference: Degree to which points are out of phase

Examiner Tips and Tricks

• Correctly label wavelength and time period on diagrams (from crest to crest)
• Avoid short or near crest labeling to prevent losing marks

Wave Energy

• Progressive Waves: Transfer energy without transferring matter
• Stationary Waves: Do not transfer energy, points vibrate about fixed positions

Additional Notes

• Ensure understanding of how wave properties and behaviors are demonstrated in experiments and diagrams
• Pay attention to the effects of wave interactions, including phase differences and energy transfer

Authors: Katie M (Physics Content Creator), Caroline Carroll (Physics Subject Lead)

These notes summarize key concepts in AS Physics related to progressive waves, focusing on their properties, behaviors, and differences from stationary waves. Additional insights include worked examples and examiner tips to aid understanding and exam preparation.