Two waves of same frequency $n$ are approaching each other with same velocity,$v = 20 \ m/s$ and interfere. The distance between two consecutive nodes is

Two identical progressive waves moving in opposite directions superimpose to produce a stationary wave. The wavelength of each progressive wave is $\lambda$. The wavelength of the stationary wave is

The correct statement about stationary waves is that

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).

The phase difference between the two particles situated on both the sides of a node in a stationary wave is ... $^o$.

The equation of a stationary wave is $Y = 10 \sin \left( \frac{\pi x}{4} \right) \cos (20 \pi t)$. The distance between two consecutive nodes in metres is