Which of the following statements is true regarding stationary waves?

The speed of a stationary wave represented by the equation $y = 0.7 \sin \left(\frac{7 \pi}{4} x\right) \cos (350 \pi t)$ is (In the given equation $x$ and $y$ are in metre and $t$ is in second). (in $m \ s^{-1}$)

Explain the reflection of a wave at a free support.

Stationary waves are produced in a $10\,m$ long stretched string. If the string vibrates in $5$ segments and the wave velocity is $20\,m/s$,the frequency is ..... $Hz$.

$A$ wave disturbance in a medium is described by $y(x, t) = 0.02 \cos(50 \pi t + \frac{\pi}{2}) \cos(10 \pi x)$, where $x$ and $y$ are in meters and $t$ is in seconds. Which statement$(s)$ is/are correct?

$A$ pulse of a wave train travels along a stretched string and reaches the fixed end of the string. It will be reflected back with