Which property distinguishes between progressive and stationary waves?

Stationary waves of frequency $300\, Hz$ are formed in a medium in which the velocity of sound is $1200\, m/s$. The distance between a node and the neighbouring antinode is ... $m$.

The $(x, y)$ coordinates of the corners of a square plate are $(0, 0), (L, 0), (L, L)$ and $(0, L).$ The edges of the plate are clamped and transverse standing waves are set up in it. If $u(x, y)$ denotes the displacement of the plate at the point $(x, y)$ at some instant of time,the possible expression$(s)$ for $u$ is(are) ($a =$ positive constant).

$A$ stretched string fixed at both ends has $m$ nodes,then the length of the string will be

For a stationary wave, $y = 12 \cos \left( \frac{\pi x}{10} \right) \sin(36\pi t) \text{ cm}$, the distance between a node and the successive antinode is (in $\text{ cm}$)

Standing waves are produced in a string $16 \ m$ long. If there are $9$ nodes between the two fixed ends of the string and the speed of the wave is $32 \ m/s$, what is the frequency of the wave (in $Hz$)?