Concept:
A progressive harmonic wave travelling along the positive x-direction is mathematically described by the general wave equation:
\[
y(x,t) = A \sin(\omega t - kx)
\]
where:
• \( A \) represents the amplitude of the wave.
• \( \omega \) is the angular frequency, defined as \( \omega = 2\pi f \).
• \( k \) is the angular wave number (or propagation constant), defined as \( k = \frac{2\pi}{\lambda} \).
The wave velocity \( v \) (the speed at which the wave profile moves through the medium) is given by the relation:
\[
v = \frac{\omega}{k}
\]
Step 1: Comparing the given wave equation with the standard progressive wave form.
The given equation of the wave is:
\[
y = 0.1 \sin(200t - 10x)
\]
By comparing this directly with the standard formula \( y = A \sin(\omega t - kx) \), we can extract the following values:
• Angular frequency, \( \omega = 200 \text{ rad/s} \)
• Wave number, \( k = 10 \text{ rad/m} \)
Step 2: Calculating the wave velocity using the extracted coefficients.
Substitute the values of \( \omega \) and \( k \) into the wave velocity formula:
\[
v = \frac{\omega}{k} = \frac{200}{10}
\]
\[
v = 20 \text{ m/s}
\]
This calculated value corresponds exactly to option (B).