The linear density of a vibrating string is ${10}^{-4} \mathrm{kg} {\mathrm{m}}^{-1}$. A transverse wave is propagating on the string, which is described by the equation $y=0.02\sin \left(x+30t\right)$, where $x$ and $y$ are in metre and the time $t$ is in second. The tension in the string is

At $t=0$, the shape of a travelling pulse is given by $\mathrm{y}(\mathrm{x},0)=\frac{4\times {10}^{-3}}{8-(\mathrm{x}{)}^2}$ where $x$ and $y$ are in metres. The wave function for the travelling pulse if the velocity of propagation is $5 \mathrm{m} {\mathrm{s}}^{-1}$ in the x direction is given by

Two particles of a medium, disturbed by the wave propagation, are at $x_1=0 \mathrm{cm}$ and $x_2=1 \mathrm{cm}$. The respective displacements (in $\mathrm{cm}$) of the particles can be given by the equations:
$y_1=2\sin 3\mathrm{\pi }t$ and $y_2=2\sin (3\mathrm{\pi }t-\frac{\mathrm{\pi }}{8})$.
The wave velocity is

The figure shows four progressive waves A, B, C and D. It can be concluded from the figure that with respect to wave A :