Study Notes
Waves transfer energy without moving matter, and can be described as oscillations or vibrations. They can be observed in various forms such as water waves, sound waves, and electromagnetic waves.
- Wave — a disturbance that transfers energy from one place to another without transferring matter. Example: Water waves in a pond.
- Transverse Wave — a wave where the displacement of the medium is perpendicular to the direction of the wave. Example: Ripples on water.
- Longitudinal Wave — a wave where the displacement of the medium is parallel to the direction of the wave. Example: Sound waves.
- Amplitude — the maximum displacement of particles in a wave. Example: Height of a wave crest.
- Wavelength — the distance between two consecutive points in phase on a wave. Example: Distance between two crests.
- Frequency — the number of oscillations per unit time. Example: Number of waves passing a point per second.
- Wave Speed — the distance a wave travels per unit time, calculated as frequency multiplied by wavelength. Example: Speed of sound in air is 330 m/s.
Exam Tips
Key Definitions to Remember
- Wave: A disturbance that transfers energy without transferring matter.
- Transverse Wave: Displacement is perpendicular to wave direction.
- Longitudinal Wave: Displacement is parallel to wave direction.
- Amplitude: Maximum displacement of particles in a wave.
- Wavelength: Distance between two consecutive points in phase.
- Frequency: Number of oscillations per unit time.
- Wave Speed: Distance a wave travels per unit time.
Common Confusions
- Confusing transverse and longitudinal waves.
- Misunderstanding how wavelength and frequency affect wave speed.
Typical Exam Questions
- What is the wavelength of a sound wave with a frequency of 264Hz and speed of 330m/s? Use v = fλ to find λ = 330/264.
- How does the wavelength of light change when it enters water from air? The wavelength decreases, but frequency remains the same.
- How can the speed of ripples in a ripple tank be changed? By altering the frequency or wavelength.
What Examiners Usually Test
- Understanding of wave properties and definitions.
- Ability to calculate wave speed using v = fλ.
- Differences between transverse and longitudinal waves.