The figure shows the shape of a part of a long string in which transverse waves are produced by attaching one end of the string to a tuning fork of frequency $250 \ Hz$. What is the velocity of the waves in $ms^{-1}$?

$A$ transverse wave is travelling along a string from left to right. The adjoining figure represents the shape of the string at a given instant. At this instant,among the following,choose the wrong statement.

$A$ transverse wave propagates in a medium with a velocity of $1450 \, m/s$. The distance between the nearest points at which the oscillations of the particles are in the opposite phase (phase difference of $\pi$) is $0.1 \, m$. What is the frequency of the wave in $Hz$?

If the equation of a progressive wave is given by $y = 3 \cos \pi (100 t - x) \text{ cm}$,then what is the wavelength of the wave in $\text{cm}$?

$A$ transverse harmonic wave on a string is described by $y = 3 \sin (36t + 0.018x + \frac{\pi}{4})$,where $x$ and $y$ are in $cm$ and $t$ is in $s$. The least distance between two successive crests in the wave is .... $m$. (in $.5$)

The equation for a spherical progressive wave is (where $r$ is the distance from the source):