Two sound waves travelling in the same direction have displacements $y_1 = a \sin(0.2 \pi x - 50 \pi t)$ and $y_2 = a \sin(0.15 \pi x - 46 \pi t)$. How many times can a listener hear sound of maximum intensity in one second?

Two strings $A$ and $B$ produce beats of frequency $\Delta f_1 > 0$. The tension in string $A$ is slightly increased and the beat frequency is found to be $\Delta f_2 > 0$. If the original frequency of $A$ is $f_0$ and $\Delta f_2 < \Delta f_1$,then the frequency of $B$ is

Two tuning forks,$A$ and $B$,produce $4$ beats per second when sounded together. The frequency of $A$ is $320 \ Hz$. When some wax is added to $B$ and it is sounded with $A$,$4$ beats per second are again heard. The frequency of $B$ is .... $Hz$.

Two tuning forks $F_1$ and $F_2$ produce $6$ beats per second when sounded together. The frequency of $F_1$ is $256 \ Hz$. When wax is applied to $F_2$,the number of beats per second remains $6$. What is the frequency of $F_2$ in $Hz$?

$A$ set of $20$ tuning forks is arranged in a series of increasing frequencies. If each fork gives $4 \; Hz$ beats with respect to the preceding fork and the frequency of the last fork is twice the frequency of the first,then the frequency of the last fork is $\dots \; Hz$.

The minimum intensity of sound is zero at a point due to two sources of nearly equal frequencies, when