Equation of a plane progressive wave is given by y =0.6sin2π(t-x/2) . On reflection from a denser medium its amplitude becomes 2/3 of the amplitude of the incident wave. The equation of the reflected wave is
(a) y =0.6sin2π(t+x/2)
(b) y=-0.4sin2π(t+x/2)
(c) y=0.4sin2π(t+x/2)
(d) y=-0.4sin2π(t-c/2)
