Which is the most important property of a stationary wave?

The equation of a standing wave in a string fixed at both ends is given as $y = 2A \sin kx \cos \omega t$. The amplitude and frequency of a particle vibrating at the midpoint between an antinode and a node are respectively:

Standing stationary waves can be obtained in an air column even if the interfering waves are

$A$ progressive wave travelling in the positive $x$-direction is given by $y = a \sin(kx - \omega t)$. It meets a fixed end at $x = 0$. The reflected wave may be given by:

$A$ standing wave with a number of loops is produced on a string fixed at both ends. Which one of the following statements is correct?

For the stationary wave $y = 4 \sin \left(\frac{\pi x}{15}\right) \cos (96 \pi t)$,the distance between a node and the next antinode is