The wave velocities of the two waves are the same, v = λ t = λ f = 8× 5 = 40m/s.t = 0.025s = T8. After the t8 period, the peaks of the solid wave and the dotted wave reach x=3m. According to the superposition of waves, it is known that the particle displacement at x=3m is 2m.

So the answer to this question is: 40,2.