Waves Topic in National 5 Physics

Introduction

Lecture by Mr. Mitchell.
Covers the "Waves" topic in National 5 Physics.
Key areas: wave parameters and behaviors, electromagnetic spectrum, refraction of light.
Learning outcomes document available on Mr. Mitchell's website.

Wave Energy Transfer: Waves transfer energy.
Types of Waves:
- Transverse Waves: Particles vibrate at 90 degrees to wave direction.
- Longitudinal Waves: Particles vibrate along the same direction as wave.
- Examples:
  - Longitudinal: Sound.
  - Transverse: Electromagnetic radiation, water waves.
Wave Calculations:
- Determine frequency, period, wavelength, amplitude, wave speed.
- Use wave diagrams for wavelength and amplitude.
- Equations needed:
  - Distance = Speed x Time
  - V = f λ (wave speed equation)
  - T = 1/f (period-frequency relation)
  - f = n/T (frequency, number of waves, time relation)
Diffraction:
- Occurs when waves pass through a gap or around an object.
- Longer wavelengths diffract more than shorter wavelengths.
- Draw wavefront diagrams to show diffraction.

Frequency and Wavelength:
- Know relative frequencies and wavelengths of EM spectrum bands.
- Radial waves have highest wavelength; Gamma rays have highest frequency.
Sources, Detectors, and Applications:
- Memorize typical sources, detectors, applications for each radiation type.
Radiation Properties:
- All EM radiations are transverse.
- Travel at speed of light (3 x 10^8 m/s).

Definition:
- Refraction: Change in wave speed when passing from one medium to another.
Effects on Wave Properties:
- Wavelength decreases when moving to a more dense medium.
- Wavelength increases when moving to a less dense medium.
Change in Direction:
- Light changes direction if angle of incidence > 0°.
- Bends towards normal (less dense to more dense).
- Bends away from normal (more dense to less dense).
Ray Diagrams:
- Identify normal, angle of incidence, angle of refraction.
- Draw and label ray diagrams; calculate angles from diagrams.