The equation of a travelling wave is y = 60 cos (1800t – 6x) where y is in microns, t in seconds and x in metres. The ratio of maximum particle velocity to velocity of wave propagation is
3.6×10−4
Maximum particle velocity =ω A
Wave velocity =ωK
Therefore, the required ratio
=ωAωK=AK=60×10−6×6=3.6×10−4