For the travelling harmonic wave ` y ( x,t) =20cos 2pi ( 10t- 0.0080x + 0.35)` where x, y are in cm and t isin s.Calculate the phase difference between oscillary motion of two points separated by a distance of
`((3 lambda)/( 4))`

Explanation

Given `y ( x, t) =2.0 cos 2 pi ( 10t - 0.008x + 0.35)`
Comparing this with `y = A cos 2pi( f t - ( x)/( lambda) +phi )`
we get, `(1)/( lambda) = 0.08`
so that `lambda = ( 1)/( 0.008) = 125 cm`
i.e., `lambda = 1.25 m`
phase difference `Delta phi = ((2pi)/( lambda )) ( Delta x ) `
where `( Delta x)` represents the path difference.
for `Delta x = ( 3lambda )/( 4) = 0.9375m`
`Delta phi = 5.0272 xx 0.9375 = 4.71 rad ( = 1.5 pi rad ) `