7. Asimple armonic progressive wave of amplitude 5cm and frequency 5Hz travelling along the positive x direction with a speed of 40m/s. Calcula i). the displacement at x = 38cm and t = 1s ii). the phase different between two points in path of the wave separate by a distance of 0.8cm iii). the phase difference between twopositions of a particle at an interv of 0.01s. 8. The equation of simple harmonic progressive wave of a source is y = = 6 sin300πtcm​