In a standing wave on a string $:-$

The correct statement about stationary waves is that

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 $Hz$)?

The equation of a stationary wave is given by $y = 0.8 \cos \left( \frac{\pi x}{20} \right) \sin (200 \pi t) \text{ cm}$. What is the distance between two consecutive nodes in cm?

$(i)$ For the wave $y(x, t) = 0.06 \sin \left(\frac{2 \pi}{3} x\right) \cos (120 \pi t)$,where $x$ and $y$ are in $m$ and $t$ is in $s$. The length of the string is $1.5 \, m$ and its mass is $3.0 \times 10^{-2} \, kg$. Do all the points on the string oscillate with the same $(a)$ frequency,$(b)$ phase,$(c)$ amplitude? Explain your answers.
$(ii)$ What is the amplitude of a point $0.375 \, m$ away from one end?

$A$ progressive wave travelling in the positive $x$-direction given by $y=a \cos (k x-\omega t)$ meets a denser surface at $x=0, t=0$. The reflected wave is then given by