https://ur.khanacademy.org/science/grade-7-science-snc-aligned/x64f379bc07a3640a:waves-and-energy/x64f379bc07a3640a:sound-an-example-of-longitudinal-waves/e/oscillatory-motion 2026-04-09T18:48:24.886883172Z آسکیلیٹری موشن آؤ پریکٹس کریں۔ vibhor exercise