Q 11-14-027NEETJEE MainMedium
In a stationary wave on a string, the distance between two consecutive nodes is $15$ cm. If the frequency is $200$ Hz, the speed of the component travelling waves is
Answer: (C) $60$ m/s
Concept. Consecutive nodes are $\dfrac{\lambda}{2}$ apart; then $v = f\lambda$.
Step 1. Wavelength. $\dfrac{\lambda}{2} = 15$ cm, so $\lambda = 0.3$ m.
Step 2. Speed. $v = 200 \times 0.3 = 60$ m/s.
Answer. $60$ m/s (Option C).
Solution by Sreeraj P, M.Sc Physics