A simple harmonic wave has the equation,
`xi=0.5 sin (314t-1.57x)`
where t, x and `xi` are in second, metre and centimetres respectively. Find the frequency and wevelength of this wave. Another wave has the equation
`xi=0.1 sin (314t-1.57x+1.57)`
Deduce the phase difference and ratio of intensities for the above two waves.