Question

Which of the following equations represents a transverse wave travelling along $-y$ axis?

• A. $x=A \sin (\omega t-k y)$
• B. $x=A \sin (\omega t+k y)$
• C. $y_{0}=A \sin (\omega t-k x)$
• D. $y_{0}=A \sin (\omega t+k x)$

Answer 1

Answer: (B)

Velocity of wave $=-\frac{\omega}{k}$
Also since the wave is travelling in the $y$ direction, displacement of the particles will be in $x$-direction.
So, equation will be of the form $x=A \sin (\omega t+k y)$
Putting positive values of $\omega$ and $k$ in the velocity equation will give negative value of velocity. Hence, wave is travelling in -ve direction.