https://www.khanacademy.org/science/in-in-class11th-physics/in-in-11th-physics-waves/in-in-introduction-to-waves/a/transverse-and-longitudinal-waves-ap1 2021-04-29T08:03:12Z Transverse and longitudinal waves review Overview of key terms and skills for waves, including how to identify longitudinal and transverse waves. article https://www.khanacademy.org/science/ap-physics-2/x0e2f5a2c:waves-sound-and-physical-optics/x0e2f5a2c:wave-properties/e/transverse-and-longitudinal-wave-exercises-ap1 2026-04-07T23:55:07.30621384Z Identifying transverse and longitudinal waves Practice identifying representations of transverse and longitudinal waves April Russell exercise https://www.khanacademy.org/science/ap-physics-2/x0e2f5a2c:waves-sound-and-physical-optics/x0e2f5a2c:wave-properties/e/wave-characteristics-ap1 2026-04-07T23:36:17.218592739Z Properties of transverse and longitudinal waves Practice identifying the characteristics of a transverse or longitudinal wave such as the wavelength, crest, and areas of compression. April Russell exercise https://www.khanacademy.org/science/bmc-grade-9-science/x345505a97fc4a662:study-of-sound/x345505a97fc4a662:characteristics-of-sound/v/sound-properties-amplitude-period-frequency-and-wavelength 2025-05-24T09:03:55.951085194Z Sound properties (Amplitude, Period, Frequency and Wavelength) Let's learn about Sound properties! Dubverse video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Sound properties (Amplitude, Period, Frequency and Wavelength) Let's learn about Sound properties! https://cdn.kastatic.org/ka-youtube-converted/Z2X49yP4VC0.mp4/Z2X49yP4VC0.mp4 317 Study of Sound https://www.khanacademy.org/science/bmc-grade-9-science/x345505a97fc4a662:study-of-sound/x345505a97fc4a662:characteristics-of-sound/v/speed-of-sound-in 2025-05-24T09:03:55.951085194Z Speed of sound Let's learn how to calculate speed of sound. Dubverse video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Speed of sound Let's learn how to calculate speed of sound. https://cdn.kastatic.org/ka-youtube-converted/32ZVNjNT3zs.mp4/32ZVNjNT3zs.mp4 225 Study of Sound https://www.khanacademy.org/science/ap-physics-2/x0e2f5a2c:waves-sound-and-physical-optics/x0e2f5a2c:wave-properties/e/numerical-wave-equation-ap1 2024-06-28T19:56:50.217380579Z Calculating wave speed, frequency, and wavelength Practice using the wave speed equation for word problems to find the frequency and wavelength of a wave.  April Russell exercise https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-sound-india/in-in-reflections-echoes-and-reverberation/v/echoes-and-reverberations 2020-06-23T07:22:40Z Echoes and reverberations Let's learn what Echoes and reverberations are. We will also see how to reduce reverberations as they could be pretty annoying Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/6axEv22HcHOGefCvwYLMnaPkZUjbK39Iu7pae43KGPq-uv6_EITGpQlmkD9DYhh9MPUa89WxyunYbRBAYViTYag9 Echoes and reverberations Let's learn what Echoes and reverberations are. We will also see how to reduce reverberations as they could be pretty annoying https://cdn.kastatic.org/ka-youtube-converted/LR-AYApQbNE.mp4/LR-AYApQbNE.mp4 537 Study of Sound https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-sound-india/in-in-reflections-echoes-and-reverberation/v/minimum-distance-for-echo 2020-06-23T07:22:41Z Minimum distance for echo How far should an obstacle be to hear an echo? Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/y7ItbO4qOznD-U7r7ggpWlpAcgCOwAuvMWmgl2CXDfAiLat-_KvHaLhNldgJKzEx1ldFJw9vQLVx3kHJPx4HY4s Minimum distance for echo How far should an obstacle be to hear an echo? https://cdn.kastatic.org/ka-youtube-converted/LnZSnlQ7shs.mp4/LnZSnlQ7shs.mp4 492 Study of Sound https://www.khanacademy.org/science/bmc-grade-9-science/x345505a97fc4a662:study-of-sound/x345505a97fc4a662:reflection-of-sound/e/echo-and-reverberation 2026-03-12T00:50:35.110583553Z Echo and Reverberation Let's solve some questions! vibhor exercise https://www.khanacademy.org/science/bmc-grade-9-science/x345505a97fc4a662:study-of-sound/x345505a97fc4a662:applications-of-reflection-of-sound/v/ultrasound-medical-imaging-in 2025-06-11T09:41:52.046979843Z Ultrasound medical imaging Let's understand UMI Skyloom (Dubbing) video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Ultrasound medical imaging Let's understand UMI https://cdn.kastatic.org/ka-youtube-converted/IakWohF_TU8.mp4/IakWohF_TU8.mp4 307 Study of Sound https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-sound-india/in-in-ultrasound/v/echolocation-sonar 2020-06-23T07:22:42Z Echolocation & S.O.N.A.R Let's learn how animals and ships use echoes to 'see' the world around them. Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/apmkAW-lPhTl4tZfgvWk0zAgcLQhZsg2fPIR1r8cvPibjWf_DYZUvgJ1bFVMXYv8ZiPFuECJGsb1uMo4zH9wncs Echolocation & S.O.N.A.R Let's learn how animals and ships use echoes to 'see' the world around them. https://cdn.kastatic.org/ka-youtube-converted/q_mEFtOGESA.mp4/q_mEFtOGESA.mp4 541 Study of Sound https://www.khanacademy.org/science/bmc-grade-9-science/x345505a97fc4a662:study-of-sound/x345505a97fc4a662:applications-of-reflection-of-sound/e/uses-of-reflection-of-sound-range-of-hearing 2026-03-12T00:50:35.110583553Z Uses of reflection of Sound and Applications of ultrasound Let's solve some questions! vibhor exercise https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:waves/x1baed5db7c1bb50b:sound-waves/v/human-ear-structure-working 2025-06-27T16:40:24.300084665Z Human ear Learn how our ears convert sound waves into a signal our brains can interpret. Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/g97yY26PTxzrz21qFPK-OvpOkUe-x1d7K5FgokmhPurKKFfkp7tgStU9DTavYaB16TY80TS09VknUEv1Y3phbanJMQ Human ear Learn how our ears convert sound waves into a signal our brains can interpret. https://cdn.kastatic.org/ka-youtube-converted/98-6WfdumZY.mp4/98-6WfdumZY.mp4 456 Study of Sound