How is the speed of a wave determined for this question?

May 12, 2016

The distance from peak to trough is $48$ $c m = 0.48$ $m$, so a full wavelength, $\lambda$, is twice this much, $0.96$ $m$. The frequency is given as $2.4$ $H z$.

For a wave, $v = f \lambda = 2.4 \times 0.96 = 2.304 \approx 2.3$ $m {s}^{-} 1$.

Explanation:

The equation $v = f \lambda$ connects the velocity in $m {s}^{-} 1$ with the wavelength, $\lambda$, in $m$ and the frequency in $H z$.

$H z$ (hertz) is the unit of frequency, and is equivalent to ${s}^{-} 1$ in SI units.

This means the units are consistent on both sides.