Figure shows a snaps hot of a sinusoidal travelling wave taken at t = 0.3s. The wavelength is 7.5 cm and the amplitude is 2 cm. If the crest P was at x = 0 at t=0), write the equation of travelling wave

Explanation

The wave has travelled a distance of 1.2 cm in 0.3s Hence speed of the wave, `v=(1.2)/(0.3)=4 cm//s`
`:.` Angular frequency `omega=(v)(k)=3.36` rad /s
Since the wave is travelling along positive x-direction and crest (maximum displacement) is at
x=0 at t=0 we can write the wave equation as, `y=A sin (kx-omegat)+(pi)/(2) (or) y(x,t)=a cos(kx-omegat)`
Therefore, the desired equation is,
`y(x,t)=(2)cos[(0.84)x-(3.36)t]cm`