A sound wave in air is represented by y=0.02sin(8πx−200πt+6π) (SI units).
During the time interval between two consecutive instants when the particle at x=0.20m crosses the equilibrium position, how far does the wave advance?
(a) 0.250m
(b) 0.0625m
(c) 0.125m
(d) 0.500m