Physics - Wave on String Question with Solution | TestHub

Key Idea Find the parameters and put in the general wave equation. Here, $$\begin{array}{rl}A& =2\mathrm{cm}\\ \text{ direction }& =+\text{ ve direction }\\ \mathrm{v}& =128{\mathrm{ms}}^{-1}\end{array}$$ and $$5\lambda =4$$ Now, $$\mathrm{k}=\frac{2\pi }{\lambda }=\frac{2\pi \times 5}{4}=7.85$$ and $$\mathrm{v}=\frac{\omega }{\mathrm{k}}=128{\mathrm{ms}}^{-1}$$ $$\begin{array}{rl}\Rightarrow \omega & =\mathrm{v}\times \mathrm{k}=128\times 7.85\\ & =1005\end{array}$$ $$\begin{array}{lll}\text{ As, }& y& =\mathrm{A}\sin (\mathrm{kx}-\omega \mathrm{t})\\ \therefore & & \mathrm{y}=2\sin (7.85\mathrm{x}-1005\mathrm{t})\\ & & =(0.02)\mathrm{m}\sin (7.85\mathrm{x}-1005\mathrm{t})\end{array}$$