Topic : displacement relation in a progressive wave

In a transverse progressive wave of amplitude A, the maximum particle velocity is four times its wave velocity. The wavelength of the wave is:-

The equation $y = A\sin^2(\omega t - kx)$ represents a wave motion

The displacement wave in a string is given as $y = 5\sin(62.8x - 157t)$. Here $y$ and $x$ are in cm and $t$ in second. The wavelength of the wave is

The sound level at a point is increased by 20 dB. By what factor is the pressure amplitude increased?