The speed of a progressive transverse wave on a string is \(18\ \mathrm{ms^{-1}}\). If the phase difference between two points on the string separated by a distance of \(3\) cm is \(90^\circ\), then the frequency of the transverse wave on the string is
Show Hint
For a progressive wave,
\[
\boxed{
\phi=\frac{2\pi x}{\lambda}
}
\]
and
\[
\boxed{
v=f\lambda.
}
\]
A phase difference of
\[
90^\circ
\]
corresponds to a path difference of
\[
\boxed{\frac{\lambda}{4}.}
\]