IGCSE Physics - Properties of Waves

Study Notes

IGCSE Physics - Properties of Waves

Electromagnetic Waves:
- Travel at a constant speed in a vacuum (3 x 10⁸ m/s)
- All have the same speed in free space
- Different types have different wavelengths and frequencies
- Examples: Gamma rays, X-rays, Ultraviolet, Visible light, Infrared, Microwaves, Radio waves
- Different electromagnetic waves have various uses (e.g., heating food, medical imaging)
Electromagnetic Waves properties:
- Different properties, such as wavelength or frequency, are NOT the same for all types of electromagnetic waves.
- Speed in a vacuum is the only property that is the same for all electromagnetic waves.
Ultrasound Waves:
- Frequency is outside the range of human hearing
- Used in medical imaging
- Speed is greater inside the body than in air
- Waves are reflected and the time taken is used to calculate depth
Longitudinal Waves:
- Example: Sound waves
- Particle vibrations are parallel to the direction of wave travel
- Characterised by compressions and rarefactions
Transverse Waves:
- Example: Water waves
- Particle vibrations are perpendicular to the direction of wave travel
- Characterised by crests and troughs
Wave Properties:
- Amplitude: maximum displacement from the rest position
- Wavelength: distance between two successive crests or troughs
- Frequency: number of waves passing a point per unit time
- Speed: product of frequency and wavelength
Wave Equation:
- speed = frequency × wavelength
Speed of Sound:
- To measure the speed of sound, a method to measure the time taken for a sound wave to travel a known distance is required. This includes a stopwatch and the use of an outdoor track of a known length