Question

A wave travelling in positive $X$ -direction with $A=0.2\, m$ has a velocity of $360\, m / \sec$ if $\lambda=60\, m$, then correct expression for the wave is

• A. $y=0.2 \sin \left[2 \pi\left(6 t+\frac{x}{60}\right)\right]$
• B. $y=0.2 \sin \left[\pi\left(6 t+\frac{x}{60}\right)\right]$
• C. $y=0.2 \sin \left[2 \pi\left(6 t-\frac{x}{60}\right)\right]$
• D. $y=0.2 \sin \left[\pi\left(6 t-\frac{x}{60}\right)\right]$

Answer 1

Answer: (C)

A wave travelling in positive $x$ -direction may be represented as $y=A \sin \frac{2 \pi}{\lambda}(v t-x)$.
On putting values $y=0.2 \sin \frac{2 \pi}{60}(360 t-x)$
$\Rightarrow y=0.2 \sin 2 \pi\left(6 t-\frac{x}{60}\right)$