Waves: Properties, EM Spectrum & Sound
Waves transfer energy and information from one place to another without transferring matter. In GCSE Physics, you compare transverse and longitudinal waves, apply the wave equation (v = fλ), investigate reflection and refraction, and learn the properties, uses, and hazards of the electromagnetic spectrum.
- Wavelength
- The distance from one point on a wave to the equivalent point on the adjacent wave.
- Frequency
- The number of waves passing a fixed point per second, measured in Hertz (Hz).
- Amplitude
- The maximum displacement of a point on a wave away from its undisturbed position.
Waves: Properties, EM Spectrum & Sound: Wave Equation (v = fλ) & Force Vector (F = ma) Simulator
Adjust physical variables on the sliders below to see real-time changes in wave geometry, resultant forces, and acceleration.
v = f × λ = 4 Hz × 2.5 m = 10.0 m/sTime Period: T = 1 ÷ 4 = 0.25 sKey Concepts & Exam Definitions (6)
- Wavelength
- The distance from one point on a wave to the equivalent point on the adjacent wave.
- Frequency
- The number of waves passing a fixed point per second, measured in Hertz (Hz).
- Amplitude
- The maximum displacement of a point on a wave away from its undisturbed position.
- Transverse Wave
- A wave in which the oscillations are at right angles to the direction of energy transfer (e.g., light).
- Longitudinal Wave
- A wave in which the oscillations are parallel to the direction of energy transfer (e.g., sound).
- Refraction
- The change in direction of a wave as it passes from one medium to another and changes speed.
Quick-Fire Flashcards (6)
Click any card to check the answer, then mark it as Known to track your progress.
What is the unit of wave frequency?
Are sound waves transverse or longitudinal?
Which electromagnetic wave has the longest wavelength?
What speed do all electromagnetic waves travel at in a vacuum?
What is the formula for wave speed?
What causes wave refraction?
Exam-Style Questions & Mark Schemes (3)
Write or think through your answer first, then click Check Mark Scheme to see the exact points examiners award marks for.
- Q1
A wave has a frequency of 50 Hz and a wavelength of 2 m. Calculate its wave speed.
Click “Check Mark Scheme” to compare your answer, Wave speed = 50 × 2 = 100 m/s.
- Q2
Describe one danger of overexposure to ultraviolet (UV) radiation.
Click “Check Mark Scheme” to compare your answer, It can cause premature skin aging and increase the risk of skin cancer.
- Q3
Explain how you would measure the speed of sound in air.
Click “Check Mark Scheme” to compare your answer, Stand a known distance (e.g., 100m) away from a wall. Clap your hands and use a stopwatch to time how long it takes to hear the echo. Speed = (2 × distance) / time.
Common Exam Questions (3)
What is the difference between transverse and longitudinal waves?
In a transverse wave (such as light or water ripples), the oscillations are perpendicular (at 90°) to the direction of energy transfer. In a longitudinal wave (such as sound), the oscillations are parallel to the direction of energy transfer, creating compressions and rarefactions.
What is the order of the electromagnetic spectrum?
In order of increasing frequency and decreasing wavelength: Radio waves, Microwaves, Infrared, Visible light, Ultraviolet, X-rays, and Gamma rays.
What is the wave equation?
The wave equation is Wave speed = Frequency × Wavelength (v = fλ), where wave speed v is in metres per second (m/s), frequency f is in hertz (Hz), and wavelength λ is in metres (m).
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