What is the wavelength at 0.5 MHz given a speed of sound of 1540 m/s?

What is the wavelength at 0.5 MHz given a speed of sound of 1540 m/s?

• A. 0.77 mm
• B. 3.08 mm
• C. 0.077 mm
• D. 77 mm

Answer: (B)

Wavelength in a medium is found from the relation λ = c / f, where c is the speed of sound and f is the frequency. With c = 1540 m/s and f = 0.5 MHz = 5 × 10^5 Hz, the wavelength is λ = 1540 / 500,000 = 0.00308 m, which is 3.08 mm. This matches the provided value. The other numbers would correspond to different frequencies (for example, about 2 MHz gives ~0.77 mm, about 20 MHz gives ~0.077 mm, and about 20 kHz gives ~77 mm), highlighting that wavelength is inversely related to frequency.

Wavelength in a medium is found from the relation λ = c / f, where c is the speed of sound and f is the frequency. With c = 1540 m/s and f = 0.5 MHz = 5 × 10^5 Hz, the wavelength is λ = 1540 / 500,000 = 0.00308 m, which is 3.08 mm. This matches the provided value. The other numbers would correspond to different frequencies (for example, about 2 MHz gives ~0.77 mm, about 20 MHz gives ~0.077 mm, and about 20 kHz gives ~77 mm), highlighting that wavelength is inversely related to frequency.