Waves

Waves transfer energy without transferring matter.

Wave properties

Transverse waves vibrate perpendicular to travel (light, water); longitudinal parallel (sound).
Key quantities: wavelength $\lambda$, frequency $f$, amplitude, period $T$.

$$v = f\lambda \qquad T = \frac{1}{f}$$

Worked example. A wave of frequency $50$ Hz and wavelength $4$ m has speed $v = f\lambda = 50 \times 4 = 200$ m s⁻¹.