The stationary wave produced on a string is represented by the equation $y = 5 \cos (\pi x / 3) \sin (40 \pi t)$. Where $x$ and $y$ are in $cm$ and $t$ is in seconds. The distance between consecutive nodes is .... $cm$.

Energy is not carried by which of the following waves?

Two travelling waves of equal amplitudes and equal frequencies move in opposite directions along a string. They interfere to produce a stationary wave whose equation is given by $y = (10 \cos \pi x \sin \frac{2 \pi t}{T}) \, cm$. The amplitude of the particle at $x = \frac{4}{3} \, cm$ will be ........ $cm$.

$Assertion :$ For the formation of stationary waves,the medium must be bounded having definite boundaries.
$Reason :$ In the stationary wave,some particles of the medium remain permanently at rest.

The following statements are given for a stationary wave:
$(a)$ Every particle has a fixed amplitude which is different from the amplitude of its nearest particle.
$(b)$ All the particles cross their mean position at the same time.
$(c)$ All the particles are oscillating with the same amplitude.
$(d)$ There is no net transfer of energy across any plane.
$(e)$ There are some particles which are always at rest.
Which of the following is correct?

The following equations represent progressive transverse waves:
$Z_1 = A \cos(\omega t - kx)$,
$Z_2 = A \cos(\omega t + kx)$,
$Z_3 = A \cos(\omega t + ky)$,
$Z_4 = A \cos(2\omega t - 2ky)$.
$A$ stationary wave will be formed by superposing: