If you set up the seventh harmonic on a string fixed at both ends,how many nodes and antinodes are set up in it?

Which is the most important property of a stationary wave?

The vibrations of a string of length $60 \, cm$ fixed at both ends are represented by the equation $y = 2 \sin \left( \frac{4 \pi x}{15} \right) \cos (96 \pi t)$,where $x$ and $y$ are in $cm$. The maximum number of loops that can be formed in it is

From the given progressive wave equations,which waves are used to produce a standing wave?
$z_1 = A \cos(\omega t - kx)$
$z_2 = A \cos(\omega t + kx)$
$z_3 = A \cos(\omega t + ky)$
$z_4 = A \cos(2\omega t - 2ky)$

$A$ standing wave having $3$ nodes and $2$ antinodes is formed between two atoms having a distance of $1.21 \ Å$ between them. The wavelength of the standing wave is (in $Å$)

$A$ wave $y = a \cos (kx + \omega t)$ superimposes on another wave to form a stationary wave having a node at $x = 0$. What is the equation of the other wave?