alleryStart learning →A sound wave has a frequency of 2000 Hz and a wavelength of 0.4 m. What is its speed?
A8 x 10^2 m/s
B5 x 10^3 m/s
C3.2 x 10^2 m/s
D2 x 10^-4 m/s
Answer & Solution
Correct answer: A. 8 x 10^2 m/s
1. Identify the known values: f = 2000 Hz and lambda = 0.4 m.
2. Use v = f x lambda, the relationship between speed, frequency, and wavelength.
3. Substitute: v = 2000 Hz x 0.4 m = 800 m/s = 8 x 10^2 m/s.
4. This matches option A.
5. Option B, 5 x 10^3 m/s, would result from dividing frequency by wavelength instead of multiplying them.
_Source: OpenStax Physics (CC BY 4.0), Ch 14 "Sound", section 14.1 Speed of Sound, Frequency, and Wavelength_
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