Which of the following is different from others?

$A$ plane progressive wave is given by $y = 2 \cos 2 \pi (330 t - x) \ m$. The frequency of the wave is: (in $Hz$)

$A$ wave is given by $y = 3 \sin 2\pi \left( \frac{t}{0.04} - \frac{x}{0.01} \right)$,where $y$ is in $cm$. The frequency of the wave and the maximum acceleration of the particle are:

$A$ transverse wave is represented by $y = \frac{10}{\pi} \sin \left( \frac{2\pi}{T}t - \frac{2\pi}{\lambda}x \right)$. For what value of the wavelength is the wave velocity twice the maximum particle velocity (in $cm$)?

The equation of a simple harmonic progressive wave is given by $y=a \sin 2 \pi(b t-c x)$. The maximum particle velocity will be half the wave velocity,if $c=$

$A$ traveling wave is described by the equation $y(x,t) = [0.05 \sin(8x - 4t)] \text{ m}$. The velocity of the wave is (All the quantities are in $SI$ units). (in $\text{ m/s}$)