The disturbance travels.
A wave transfers energy without a net transport of the medium across the whole path. In a transverse wave particle oscillation is perpendicular to propagation; in a longitudinal wave it is parallel. Sound in air is longitudinal; electromagnetic waves are transverse and do not need a material medium.
Frequency is cycles per second and period is time per cycle. Adjacent points one wavelength apart are in phase. In a fixed medium, changing source frequency changes wavelength so that v = fλ remains satisfied.
A travelling transverse wave
Explore the relationship
Wave speed 4 m s⁻¹ and amplitude 1 m. The graph is a snapshot; the animation shows propagation.
Tap or focus a plotted point to read its values.
View plotted data as a table
| Series | Position / m | Displacement / m |
|---|---|---|
| Displacement / m | 0 | 0 |
| Displacement / m | 0.133333 | 0.207912 |
| Displacement / m | 0.266667 | 0.406737 |
| Displacement / m | 0.4 | 0.587785 |
| Displacement / m | 0.533333 | 0.743145 |
| Displacement / m | 0.666667 | 0.866025 |
| Displacement / m | 0.8 | 0.951057 |
| Displacement / m | 0.933333 | 0.994522 |
| Displacement / m | 1.06667 | 0.994522 |
| Displacement / m | 1.2 | 0.951057 |
| Displacement / m | 1.33333 | 0.866025 |
| Displacement / m | 1.46667 | 0.743145 |
| Displacement / m | 1.6 | 0.587785 |
| Displacement / m | 1.73333 | 0.406737 |
| Displacement / m | 1.86667 | 0.207912 |
| Displacement / m | 2 | 1.22465e-16 |
| Displacement / m | 2.13333 | -0.207912 |
| Displacement / m | 2.26667 | -0.406737 |
| Displacement / m | 2.4 | -0.587785 |
| Displacement / m | 2.53333 | -0.743145 |
| Displacement / m | 2.66667 | -0.866025 |
| Displacement / m | 2.8 | -0.951057 |
| Displacement / m | 2.93333 | -0.994522 |
| Displacement / m | 3.06667 | -0.994522 |
| Displacement / m | 3.2 | -0.951057 |
| Displacement / m | 3.33333 | -0.866025 |
| Displacement / m | 3.46667 | -0.743145 |
| Displacement / m | 3.6 | -0.587785 |
| Displacement / m | 3.73333 | -0.406737 |
| Displacement / m | 3.86667 | -0.207912 |
| Displacement / m | 4 | -2.44929e-16 |
| Displacement / m | 4.13333 | 0.207912 |
| Displacement / m | 4.26667 | 0.406737 |
| Displacement / m | 4.4 | 0.587785 |
| Displacement / m | 4.53333 | 0.743145 |
| Displacement / m | 4.66667 | 0.866025 |
| Displacement / m | 4.8 | 0.951057 |
| Displacement / m | 4.93333 | 0.994522 |
| Displacement / m | 5.06667 | 0.994522 |
| Displacement / m | 5.2 | 0.951057 |
| Displacement / m | 5.33333 | 0.866025 |
| Displacement / m | 5.46667 | 0.743145 |
| Displacement / m | 5.6 | 0.587785 |
| Displacement / m | 5.73333 | 0.406737 |
| Displacement / m | 5.86667 | 0.207912 |
| Displacement / m | 6 | 3.67394e-16 |
| Displacement / m | 6.13333 | -0.207912 |
| Displacement / m | 6.26667 | -0.406737 |
| Displacement / m | 6.4 | -0.587785 |
| Displacement / m | 6.53333 | -0.743145 |
| Displacement / m | 6.66667 | -0.866025 |
| Displacement / m | 6.8 | -0.951057 |
| Displacement / m | 6.93333 | -0.994522 |
| Displacement / m | 7.06667 | -0.994522 |
| Displacement / m | 7.2 | -0.951057 |
| Displacement / m | 7.33333 | -0.866025 |
| Displacement / m | 7.46667 | -0.743145 |
| Displacement / m | 7.6 | -0.587785 |
| Displacement / m | 7.73333 | -0.406737 |
| Displacement / m | 7.86667 | -0.207912 |
| Displacement / m | 8 | -4.89859e-16 |
Explore: Change frequency at fixed speed and watch the wavelength adjust.
A wave has f = 5 Hz and λ = 0.8 m.
- v = fλ = 5 × 0.8 = 4 .
- T = = 0.20 s.
Assumed knowledge
Frequency units and graph axes.
Learning checkpoints & source
YOUR LEARNING CHECKPOINT- Relate wavelength, frequency and wave speed.
- Compare transverse and longitudinal waves.