A 1000 Hz tone in air has a wavelength of about one foot

Evidence

It is always a good idea to check the dimensional units of physical expressions. This is called dimensional analysis. We want the wavelength to correspond to a length, of course, which means the answer should have dimensions of meters (m). The formula λ = c/f is dimensionally correct, since c is a speed, in m/s, and f has dimensions of inverse seconds. (Frequency is the number of events per second.) A 1000 Hz tone thus has a wavelength of λ = 343/1000 = 0.343 m, or about a foot. — Eric J. Heller, Why You Hear What You Hear- An…, 136

Categorization

• SHARE: The ‘1000 Hz is about a foot’ rule of thumb is handy for anyone doing quick acoustic calculations.
• DEFINE: Introduces dimensional analysis and grounds the speed-frequency-wavelength relation with a concrete number.