เครื่องคำนวณความยาวคลื่น – λ = v/f

วิธีใช้เครื่องคิดเลขนี้

1. ป้อนCalculate
2. ป้อนFrequency (Hz) or Wavelength (m)
3. ป้อนWave Medium
4. คลิกปุ่มคำนวณ
5. อ่านผลลัพธ์ที่แสดงด้านล่างเครื่องคิดเลข

The Wavelength Formula: λ = v/f

Wavelength (λ) equals wave speed (v) divided by frequency (f). For electromagnetic waves in a vacuum, v = c = 299,792,458 m/s (speed of light). For sound in air at 20°C, v ≈ 343 m/s.

A 500 MHz radio wave has λ = 299,792,458 ÷ 500,000,000 = 0.6 m (60 cm). A 1000 Hz sound wave in air has λ = 343 ÷ 1000 = 0.343 m (34.3 cm).

Electromagnetic Spectrum by Wavelength

Radio waves: > 1 mm. Microwaves: 1 mm – 10 cm. Infrared: 700 nm – 1 mm. Visible light: 380–700 nm (violet to red). Ultraviolet: 10–380 nm. X-rays: 0.01–10 nm. Gamma rays: < 0.01 nm.

Visible light covers only a tiny fraction of the full electromagnetic spectrum. Human vision peaks around 555 nm (green-yellow).

Sound Wavelengths and Human Hearing

Human hearing range: 20 Hz – 20,000 Hz. At 343 m/s (air at 20°C):

20 Hz (lowest): λ = 17.2 m. 1000 Hz (speech): λ = 34.3 cm. 20,000 Hz (highest): λ = 1.7 cm.

Sound wavelengths determine room acoustics. Bass frequencies (long wavelengths) require large speakers and rooms. High frequencies (short wavelengths) are easily absorbed by soft materials.