Q. The equation for the displacement of a stretched string is given by: y = 4sin2$\mathrm{\pi }\left(\frac{\mathrm{t}}{0.02}-\frac{\mathrm{x}}{100}\right)$. Where y and x are in cm and t in sec. The (i) frequency (ii) velocity of the wave (ii) maximum particle velocity are: 
(a) 50 Hz, 50 m/s, 20$\mathrm{\pi }$ m/s                     (b) 50 Hz, 20 m/s, 50 m/s 
(c) 50 Hz, 50 m/s, 2$\mathrm{\pi }$ m/s                       (d) 50 Hz, 50 m/s, 4$\mathrm{\pi }$ m/s