https://www.khanacademy.org/science/ap-physics-c-mechanics/x077f5683c1428fac:work-energy-and-power/x077f5683c1428fac:conservation-of-energy/v/conservation-of-energy-part-1 2026-01-24T14:20:37.342605745Z Conservation of energy (part 1) Mechanical energy is the sum of a system’s kinetic and potential energies. If the work done on a selected system is zero and there are no nonconservative interactions within the system, the total mechanical energy of the system is constant. If the work done on a selected system is nonzero, energy is transferred between the system and the environment. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/deeb4c63-1437-41e8-a687-02ca90cef42b_1280_720_base.png Conservation of energy (part 1) Mechanical energy is the sum of a system’s kinetic and potential energies. If the work done on a selected system is zero and there are no nonconservative interactions within the system, the total mechanical energy of the system is constant. If the work done on a selected system is nonzero, energy is transferred between the system and the environment. https://cdn.kastatic.org/ka-youtube-converted/GdDrYgXzBew.mp4/GdDrYgXzBew.mp4 1043 Conservation of energy https://www.khanacademy.org/science/ap-physics-c-mechanics/x077f5683c1428fac:work-energy-and-power/x077f5683c1428fac:conservation-of-energy/v/conservation-of-energy-part-2 2026-01-26T13:20:30.552724222Z Conservation of energy (part 2) Energy is conserved in all interactions. Any change to a type of energy within a system must be balanced by an equivalent change of other types of energies within the system, or by a transfer of energy between the system and its surroundings. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/78837dfc-ce4e-4d8f-9843-03bccc986d0c_1280_720_base.png Conservation of energy (part 2) Energy is conserved in all interactions. Any change to a type of energy within a system must be balanced by an equivalent change of other types of energies within the system, or by a transfer of energy between the system and its surroundings. https://cdn.kastatic.org/ka-youtube-converted/JrVd-czHl_g.mp4/JrVd-czHl_g.mp4 640 Conservation of energy https://www.khanacademy.org/science/ap-physics-c-mechanics/x077f5683c1428fac:work-energy-and-power/x077f5683c1428fac:conservation-of-energy/e/conservation-of-energy-law-ap-physics-1 2025-12-21T23:40:11.622015733Z Conservation of energy Practice applying conservation of energy in this set of free practice questions. Sean Boston exercise https://www.khanacademy.org/science/ap-physics-c-mechanics/x077f5683c1428fac:work-energy-and-power/x077f5683c1428fac:conservation-of-energy/e/conservation-of-energy 2025-12-21T23:42:59.505332053Z Energy and systems Check your understanding of energy and systems in this set of free practice questions. exercise https://www.khanacademy.org/science/ap-physics-c-mechanics/x077f5683c1428fac:work-energy-and-power/x077f5683c1428fac:conservation-of-energy/e/energy-bar-charts 2026-06-19T17:56:42.733541135Z Energy bar charts Apply your knowledge of energy bar charts in this set of free practice questions. Molly Sauder exercise