Find the beat frequency when a 386 Hz and a 389 Hz tuning fork are struck at the same time.

Question:

Find the beat frequency when a 386 Hz and a 389 Hz tuning fork are struck at the same time.

Beat Frequency

Beat is the phenomenon in which alternating loud and soft sound (periodic variation) is is produced when two sound wave of slightly different frequency approach the same point. The beat is produced by the interference of the sound waves in time. The beat frequency is defined as the difference in frequencies of the two sound waves.

Given :

• The frequency of the first sound is, {eq}f_1 = 386 \ Hz {/eq}
• The frequency of the second sound is, {eq}f_2 = 389 \ Hz {/eq}

The beat frequency corresponding to these two sounds is given by:

{eq}\begin{align*} \text{Beat frequency} &= f_2-f_1 \\ \text{Beat frequency} &= 389 - 386 \\ \color{blue}{ \text{Beat frequency} } &= \color{blue}{ \boxed{ 3 \ Hz } } \end{align*} {/eq}