The equation of undamped oscillations has the form: x = 10 ^ -6 * sin10 ^ 2 * t, m. Wavelength 15 m. Write the plane wave equation. Determine: the displacement of a point of the medium located at a distance of 20 m from the source at time 0.01 s, the phase difference of the oscillations of points located at a distance of 15 m and 20 m from the source.

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