Question

A wave is represented by the equation y = 0.1 sin (100$\pi$t - kx). If wave velocity is 100 m $s^{-1}$, its wave number is equal to

• A. 1 $m^{-1}$
• B. 2 $m^{-1}$
• C. $\pi$$m^{-1}$
• D. $2\pi$$m^{-1}$

Answer 1

Answer: (C)

$\pi$$m^{-1}$

Given,

$v=100m/s$

A wave is represented by the equation,

$y=0.1sin(100\pi t-kx)$

$\omega =100\pi$

wave velocity, $v=\frac{\omega }{k}$

$k=\frac{\omega }{v}$

Wave number, $k=\frac{100\pi }{100}$

$k=\pi m^{-1}$

The correct option is C.