Question 97: Waves

Question

The distance between two consecutive points with phase difference of 60$$^\circ$$ in a wave of frequency 500 Hz is 6.0 m. The velocity with which wave is travelling is __________ km/s

Accepted Answer

$$
\begin{aligned}
& \Delta x=\frac{\lambda}{2 \pi} 	imes\left(\frac{\pi}{3}ight)=\left(\frac{\lambda}{6}ight) \\
& \Rightarrow \quad \frac{\lambda}{6}=6 \mathrm{~m} \\
& \quad \lambda=36 \mathrm{~m} \\
& U=f\lambda=500 \mathrm{~Hz} 	imes 36 \\
& =18000 \mathrm{~m} / \mathrm{s} \\
& =18 \mathrm{~km} / \mathrm{s}
\end{aligned}
$$

Waves

The distance between two consecutive points with phase difference of 60$^\circ$ in a wave of frequency 500 Hz is 6.0 m. The velocity with which wave is travelling is __________ km/s

Choose the correct answer: