Question 27 of 142
A sinusoidal wave of wavelength 7.5 cm travels a distance of 1.2 cm along the x -direction in 0.3 sec. The crest is at at and maximum displacement of the wave is 2 cm. Which equation correctly represents this wave ?
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Answer: (A)
$\begin{aligned}
& \mathrm{v}=\frac{\text { distance }}{\text { time }} \\
& \mathrm{v}=\frac{12}{0.3}=4 \mathrm{~cm} / \mathrm{s} \\
& \mathrm{k}=\frac{2 \pi}{\lambda}=\frac{2 \pi}{7.5}=\frac{4 \pi}{15}=0.83 \\
& \mathrm{v}=\frac{\omega}{\mathrm{k}} \Rightarrow \omega=\mathrm{vk}=4 \times \frac{4 \pi}{15}=3.35
\end{aligned}$
So
& \mathrm{v}=\frac{\text { distance }}{\text { time }} \\
& \mathrm{v}=\frac{12}{0.3}=4 \mathrm{~cm} / \mathrm{s} \\
& \mathrm{k}=\frac{2 \pi}{\lambda}=\frac{2 \pi}{7.5}=\frac{4 \pi}{15}=0.83 \\
& \mathrm{v}=\frac{\omega}{\mathrm{k}} \Rightarrow \omega=\mathrm{vk}=4 \times \frac{4 \pi}{15}=3.35
\end{aligned}$
So