Q115 / 125 · BITSAT 2021 · Physics
The displacement y of a particle in a medium can be expressed as, $y=10^{-6} \sin \left(100 t+20 x+\frac{\pi}{4}\right) m$ where $t$ is in second and $x$ in meter. The speed of the wave is
- A$20 \mathrm{~m} / \mathrm{s}$
- Correct answerB$5 \mathrm{~m} / \mathrm{s}$
- C$2000 \mathrm{~m} / \mathrm{s}$
- D$5 \pi \mathrm{m} / \mathrm{s}$
Solution
From equation given,
$\begin{array}{l}
\omega=100 \\
\text { and } \mathrm{k}=20 \\
\mathrm{v}=\frac{\omega}{\mathrm{k}}=\frac{100}{20}=5 \mathrm{~m} / \mathrm{s}
\end{array}$
Hence, the correct answer is option: 'B'.