https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-work-energy/in-in-energy/v/energy-intro-kinetic-potential-work-energy-physics-khan-academy 2020-06-23T07:22:40Z Energy intro (kinetic & potential) Let's explore what kinetic & potential energies are. Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/u_-59Qmfsihpnz1XX5WMvkIgGbosPyOphG2aFqhLwFt_p3Kqxcfm0JxweGNHCCa8eK1fxyaPD91AF5LXioTQPVZ5 Energy intro (kinetic & potential) Let's explore what kinetic & potential energies are. https://cdn.kastatic.org/ka-youtube-converted/e-CAW3fN68M.mp4/e-CAW3fN68M.mp4 596 Mechanical Energy https://www.khanacademy.org/science/up-science-grade-6-revision-course-full-term/x017c12e57b64cfa8:week-3/x017c12e57b64cfa8:work-and-energy/e/mechanical-energy 2026-04-08T00:54:09.631945657Z Mechanical energy and its types Let's solve some questions of mechanical energy Vibhor Pandey exercise https://www.khanacademy.org/science/up-science-grade-6-revision-course-full-term/x017c12e57b64cfa8:week-3/x017c12e57b64cfa8:work-and-energy/v/kinetic-energy 2023-06-26T04:10:39.513125705Z Kinetic energy What kind of energy do moving objects have? Let's find out! Vibhor Pandey video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Kinetic energy What kind of energy do moving objects have? Let's find out! https://cdn.kastatic.org/ka-youtube-converted/VCYis8ruZdI.mp4/VCYis8ruZdI.mp4 172 Mechanical Energy https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-work-energy/in-in-energy/v/kinetic-energy-derivation-work-energy-physics-khan-academy 2020-06-23T07:22:40Z Kinetic energy derivation Let's derive the K.E. expression 1/2 m v^2.   Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/74PtyEBmE6LMW5ZH6UKT1Wm3WWJvUhEFsukZXrqGJm0yuzxTtCEtQ4FuLg5AjjMgVV6eHh00LXpwbzb1zBZlM9o Kinetic energy derivation Let's derive the K.E. expression 1/2 m v^2.   https://cdn.kastatic.org/ka-youtube-converted/Kmr5w1j0neA.mp4/Kmr5w1j0neA.mp4 714 Mechanical Energy https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:energy-work-and-power/x0e04e0cb682fb793:kinetic-and-potential-energy/e/kinetic-energy-exercises-ap1 2025-02-17T09:04:27.796626334Z Using the kinetic energy equation Practice using the equation for kinetic energy to find mass, velocity, and kinetic energy.  April Russell exercise https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-work-energy/in-in-work-energy-theorem/v/work-done-from-kinetic-energy-solved-example-work-energy-physics-khan-academy 2020-06-23T07:22:41Z Work done from kinetic energy - solved example Let's calculate work done when velocities are given.  Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/Lr4wjflZdpQNyvbGyyvP2VCqiBT9XsioGyVM9jZbt8kqTQ_YFeLxFq9z23rE2cIqE_11f3u9MYUaNIeThvoWUSyh Work done from kinetic energy - solved example Let's calculate work done when velocities are given.  https://cdn.kastatic.org/ka-youtube-converted/LexvE1LV0aE.mp4/LexvE1LV0aE.mp4 512 Mechanical Energy https://www.khanacademy.org/science/in-in-class11th-physics/in-in-class11th-physics-work-energy-and-power/in-in-class11-work-energy-theorem/e/work-energy-theorem-exercises-ap1 2026-03-25T13:20:47.939559562Z Calculating change in kinetic energy from a force Find the change in kinetic energy from a force using the work energy theorem. April Russell exercise https://www.khanacademy.org/science/up-science-grade-6-revision-course-full-term/x017c12e57b64cfa8:week-3/x017c12e57b64cfa8:work-and-energy/v/potential-energy 2023-06-26T04:10:39.513125705Z Potential energy What kind of energy does a stretched rubber band, or a compressed spring have? Let's find out! Vibhor Pandey video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Potential energy What kind of energy does a stretched rubber band, or a compressed spring have? Let's find out! https://cdn.kastatic.org/ka-youtube-converted/V0lrc4kud2o.mp4/V0lrc4kud2o.mp4 259 Mechanical Energy https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:energy/x1baed5db7c1bb50b:potential-energy/v/ms-potential-energy 2025-07-01T10:10:08.145512912Z Potential energy Potential energy is stored in a system of objects interacting through non-contact forces. Types include gravitational potential energy and electric potential energy. The amount of potential energy in a system depends on the distance between the interacting objects. When the distance between two attracting objects increases, the potential energy stored in the system increases. When the distance between two repelling objects increases, the potential energy stored in the system decreases. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/74ba4c31-d810-4429-8a43-c88e3a63eed2_1280_720_base.png Potential energy Potential energy is stored in a system of objects interacting through non-contact forces. Types include gravitational potential energy and electric potential energy. The amount of potential energy in a system depends on the distance between the interacting objects. When the distance between two attracting objects increases, the potential energy stored in the system increases. When the distance between two repelling objects increases, the potential energy stored in the system decreases. https://cdn.kastatic.org/ka-youtube-converted/5VVY0MSkrd0.mp4/5VVY0MSkrd0.mp4 514 Mechanical Energy https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-work-energy/in-in-energy/v/gravitational-potential-energy-derivation-work-energy-physics-khan-academy 2020-06-23T07:22:42Z Gravitational potential energy derivation Let's derive expression for gravitational potential energy.  Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/P2qiltiVUzc3i3Ne1cvL7szFYmNjlGgr7Ts7ehpAv3kqvdMlC2PZeSKmqJtStob6K4UoTRQ4_SD2FYwOc4UMiHMl Gravitational potential energy derivation Let's derive expression for gravitational potential energy.  https://cdn.kastatic.org/ka-youtube-converted/BlQg-0WQk9k.mp4/BlQg-0WQk9k.mp4 506 Mechanical Energy https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-work-energy/in-in-energy/v/work-done-by-gravity-path-independent-work-energy-physics-khan-academy 2020-06-23T07:22:43Z Work done by gravity (path independent) Let's see why work done by gravity is path independent.  Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/MV0A7KWtHC2Eiqk7dCgL9eAJtUz9fiAU6p_x776tcHqSduitLCCQ67wDr-RVVmC-8vdGE6BCar8vXkK-Naf93ZTWGQ Work done by gravity (path independent) Let's see why work done by gravity is path independent.  https://cdn.kastatic.org/ka-youtube-converted/5xNVxec4cME.mp4/5xNVxec4cME.mp4 888 Mechanical Energy https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:energy/x1baed5db7c1bb50b:potential-energy/e/understand-potential-energy 2026-04-27T10:10:46.754795089Z Understand: Potential energy Check your understanding of potential energy in this set of free practice questions. Khan Academy exercise https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:energy/x1baed5db7c1bb50b:potential-energy/e/apply-potentialenergy 2026-05-01T13:40:34.883034315Z Apply: Potential energy Apply your knowledge of potential energy in this set of free practice questions. Molly Sauder exercise https://www.khanacademy.org/science/class-7-science/x0c8b40bd4b242f0b:energy/x0c8b40bd4b242f0b:conversion-of-energy/v/transformation-of-energy 2023-06-26T04:10:39.513125705Z Transformation of energy Energy can be transformed from one from to another. Let's understand that with a simple activity! Vibhor Pandey video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Transformation of energy Energy can be transformed from one from to another. Let's understand that with a simple activity! https://cdn.kastatic.org/ka-youtube-converted/GIpZSn3M5Ww.mp4/GIpZSn3M5Ww.mp4 135 Mechanical Energy https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:energy-work-and-power/x0e04e0cb682fb793:conservation-fo-energy/e/conservation-of-energy-in 2026-04-07T22:23:57.656416987Z Transformations of energy Let's solve some questions! vibhor exercise https://www.khanacademy.org/science/in-in-class-11-physics-cbse-hindi/in-in-11-work-energy-and-power-hindi/conservation-of-energy-hindi/e/conservation-of-energy-conceptual-exercises-ap1 2026-04-08T00:36:09.500768563Z Changes in energy Practice applying the conservation of energy to predict changes in kinetic energy, potential energy, and velocity. April Russell exercise https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:energy/x1baed5db7c1bb50b:conservation-of-energy/v/ms-conservation-of-energy 2025-07-01T10:10:08.145512912Z Conservation of energy If a system is isolated so that no energy is enters or leaves the system, the total amount of energy in the system remains the same over time. Energy may convert between kinetic and potential, but the total amount is constant. If energy is transferred into or out of the system, the total energy of the system does change. Energy often transfers out of systems as sound and thermal energy. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/5340bfae-2573-455a-869e-47e2556e3015_1280_720_base.png Conservation of energy If a system is isolated so that no energy is enters or leaves the system, the total amount of energy in the system remains the same over time. Energy may convert between kinetic and potential, but the total amount is constant. If energy is transferred into or out of the system, the total energy of the system does change. Energy often transfers out of systems as sound and thermal energy. https://cdn.kastatic.org/ka-youtube-converted/Tf4A93763Bw.mp4/Tf4A93763Bw.mp4 429 Mechanical Energy https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-work-energy/in-in-law-of-conservation-of-energy/v/law-of-energy-conservation-work-energy-physics-khan-academy 2020-06-23T07:22:40Z Law of energy conservation Let's explore the law of conservation of energy. Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/Dtwjx3fL56QdUjrIobviYke_J1wmHabfJEm_h2CdpfAizQQagC_-4KBdrfCSc-sO4I1bXrMg5PoNkcN18FG_ydst Law of energy conservation Let's explore the law of conservation of energy. https://cdn.kastatic.org/ka-youtube-converted/b7k1uw8_ZtY.mp4/b7k1uw8_ZtY.mp4 787 Mechanical Energy https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-work-energy/in-in-law-of-conservation-of-energy/v/energy-conservation-solved-example-work-energy-physics-khan-academy 2025-01-02T23:26:09.730705957Z Conservation of energy examples Practice two problems involving conservation of energy. Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/eRpthabXUxS0tL90GF6SUI-79UtdZNvlmE00dcZkj35A8cBbA7qGy78B1soTnD1NMeZEEAXPfHzfiAE_YriEEKGU Conservation of energy examples Practice two problems involving conservation of energy. https://cdn.kastatic.org/ka-youtube-converted/O-9BXpHcOdQ.mp4/O-9BXpHcOdQ.mp4 575 Mechanical Energy https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:energy-work-and-power/x0e04e0cb682fb793:conservation-fo-energy/e/understand-changes-in-energy 2026-04-27T10:10:46.754795089Z Understand: Conservation of energy Check your understanding of conservation of energy in this set of free practice questions. Khan Academy exercise https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:energy/x1baed5db7c1bb50b:conservation-of-energy/e/apply-changes-in-energy 2026-05-01T13:40:34.883034315Z Apply: Conservation of energy Apply your knowledge of conservation of energy in this set of free practice questions. Khan Academy exercise https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:explore-physics-through-simulations/x1baed5db7c1bb50b:explore-conservation-of-energy-through-simulations/e/phet-simulation-exploring-conservation-of-energy 2026-04-07T22:23:57.656416987Z PhET challenge: Conservation of energy Use a PhET simulation to test your knowledge of conservation of energy with this set of free, standards-aligned practice questions. Emily Cizmas exercise