Grade 11 · Practical
Investigation: the speed of sound / wave properties
Prescribed investigations · about 3 min
Wavelength, amplitude, crest and trough.Aim: to determine the relationship between frequency and wavelength for a wave at constant speed.
Key points- Apparatus: signal generator, speaker, resonance tube or ripple tank, ruler.
- Method: vary the frequency and measure the corresponding wavelength.
- Plot wavelength against 1/frequency: a straight line whose gradient is the wave speed.
- v = f·λ should give a consistent value across all readings.
- Resonance — a large amplitude at a natural frequency.
- Wave speed — the constant product of f and λ in a given medium.
EXAM TIP
identify sources of error (measuring the tube length, reaction time) — evaluation marks are guaranteed in every practical question.