a) y = 0.6 sin 2π(t+x/2)

b) y = -0.4 sin 2π(t+x/2)

c) y = 0.4 sin 2π(t+x/2)

d) y = -0.4 sin 2π(t-x/2)

Answer:

The correct option is b) y = -0.4 sin 2π(t+x/2)

Explanation:

The amplitude of the reflected wave = 32​×0.6 =0.4
There is a change of phase by $\pi$on reflection from a denser medium. Therefore, the equation of the reflected wave is :
y = 0.4sin2π(t + x/2 ​+ π)

y =−0.4sin2π(t + x​/2)