\(y_s=2y_0 sin{kx}cos{\omega t}\)

\(y=(7cm)sin[2 \pi (\frac{t}{T}-\frac{2x}{\pi cm})]=(7cm)sin[\frac{2\pi t}{T}-\frac{4x}{cm}]\)

\(k=\frac{4}{cm}\), \(\omega=\frac{2\pi}{T}\), \(y_0=7cm\)

\(y=(14cm)sin(\frac{4x}{m})cos(\frac{2\pi t}{T})\)

amptitude =14cm

wavelength=\(\lambda=\frac{2\pi}{k}=1.57cm\)

the length of one loop is \(\frac{\lambda}{2}=0.785cm\)