Question

The wavelength of sound emmitted by source is 1. 7 x 10-2m. Calculate frequency of the sound ,if its velocity is 343ms-1

Answer 1

Approximately
`2.0 * 10^(4)\; {\rm Hz}`.

Step-by-step explanation:

The frequency
`f` of a wave is the number of wave cycles completed in unit time (usually one second.)

The velocity
`v` of a wave gives the distance travelled in unit time. The wavelength
`\lambda` of a wave gives the distance travelled during each wave cycle.

In order to find the frequency of this wave, divide velocity by wavelength:

`\begin{aligned} & (\text{number of cycles in unit time}) \\ =\; & \frac{(\text{distance travelled in unit time})}{(\text{distance travelled in each cycle})}\end{aligned}`.

`\begin{aligned}f &= (v)/(\lambda) \\ &= \frac{343\; {\rm m\cdot s^(-1)}}{1.7 * 10^(-2)\; {\rm m}} \\ &\approx 2.0 * 10^(4)\; {\rm s^(-1)}\end{aligned}`.

Note that
`1\; {\rm s^(-1)} = 1\; {\rm Hz}`. Thus, the frequency of this wave would be approximately
`2.0 * 10^(4)\; {\rm Hz}`.