Stationary Waves & Vibrating Strings question from NEET 1994 (AIPMT)

Answer: (a)

1. Compare with $y = A\sin(\omega t)\cos(kx)$: $\omega = 100\text{ rad/s}$, $k = 0.01\text{ m}^{-1}$.
2. Speed of the component waves $v = \dfrac{\omega}{k} = \dfrac{100}{0.01} = 10^4\text{ m/s}$.
3. So the answer is (a) $10^4\text{ m/s}$.