Question

A sound wave has a frequency of 192 Hz and travels the length of a football field, 91.4 m, in 0.27 s. What is the period of the wave?

• A. $1.3\times {10}^{-3}s$
• B. $2.6\times {10}^{-3}s$
• C. $5.2\times {10}^{-3}s$
• D. $7.8\times {10}^{-3}s$

Answer 1

Answer: (C)

$5.2\times {10}^{-3}s$

The frequency (f) of a wave is the number of full wave forms generated per second. This is the same as the number of repetitions per second or the number of oscillations per second.
Time Period (T) is the number of seconds per waveform, or the number of seconds per oscillation. It is clear that frequency and period are reciprocals.
That is, $T=\frac{1}{f}=\frac{1}{192}=0.0052seconds$.
Hence, the time period of the wave is $5.2\times {10}^{-3}seconds$.