https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-work-energy/in-in-work/v/positive-negative-work-work-energy-physics-khan-academy 2020-06-23T07:22:40Z Positive & negative work Let's explore when work is positive & negative.  Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/ulqZu0VdJbUz4q8cfbnLQS77l3XCBP3MgP6RyAFCRs3TphIt7zmXuKaIne1zqKe0QVdgFjVycVLk4iS-kbdQ0VYcdg Positive & negative work Let's explore when work is positive & negative.  https://cdn.kastatic.org/ka-youtube-converted/WL7__D14kGc.mp4/WL7__D14kGc.mp4 486 Work and Energy https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-work-energy/in-in-work/v/work-done-on-liftingfalling-things-solved-numerical-work-energy-physics-khan-academy 2020-06-23T07:22:40Z Work done on lifting/falling things - Solved numerical Let's calculate 2 problems on work done on lifting & falling bodies.  Mahesh Shenoy video https://cdn.kastatic.org/googleusercontent/UVW_EGTFtDlKbXwrealu_SPgMjUtL1Edym8XbOs7H_za3gr8Hy4ZvJIPzaOW7u3xoyWh5DFvMKznMDYRKUYSSM7Q Work done on lifting/falling things - Solved numerical Let's calculate 2 problems on work done on lifting & falling bodies.  https://cdn.kastatic.org/ka-youtube-converted/lOC-RDGOM3s.mp4/lOC-RDGOM3s.mp4 595 Work and Energy https://www.khanacademy.org/science/bridge-course-class-11th-physics/x4c0d503cda725c32:work-and-energy/x4c0d503cda725c32:work-and-kinetic-energy/e/identify-if-the-work-done-is-positive-negative-or-zero 2025-03-07T16:50:49.734868403Z Identify if the work done is positive, negative or zero Let's solve some questions! vibhor 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 Work and Energy https://www.khanacademy.org/science/bridge-course-class-11th-physics/x4c0d503cda725c32:work-and-energy/x4c0d503cda725c32:potential-energy/e/calculating-potential-energy-at-a-height 2026-03-05T11:40:39.067185171Z Calculating Potential energy at a height Let's solve some questions! vibhor exercise 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 Work and 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 Work and Energy https://www.khanacademy.org/science/up-class-9th-science/x699e14d392a80aeb:work-and-energy/x699e14d392a80aeb:energy/e/calculating-kinetic-energy 2025-04-09T10:29:21.798362485Z Calculating Kinetic energy Let's solve some questions! vibhor exercise https://www.khanacademy.org/science/bridge-course-class-11th-physics/x4c0d503cda725c32:work-and-energy/x4c0d503cda725c32:work-and-kinetic-energy/e/calculating-kinetic-energy-when-a-force-is-applied 2025-04-09T10:12:02.040424533Z Calculating change in Kinetic energy when a force is applied Let's solve some questions! vibhor exercise https://www.khanacademy.org/science/up-class-9th-science/x699e14d392a80aeb:work-and-energy/x699e14d392a80aeb:energy/e/optional-more-questions-on-calculating-ke-and-change-in-ke-when-a-force-is-applied 2026-03-05T11:40:39.067185171Z Optional: More questions on calculating KE and change in KE when a force is applied Let's solve some questions! vibhor exercise 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 Work and Energy https://www.khanacademy.org/science/bridge-course-class-11th-physics/x4c0d503cda725c32:work-and-energy/x4c0d503cda725c32:potential-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/9th-grade-melcs/x48ae216379e0830b:4th-quarter/x48ae216379e0830b:conservation/e/conservation-of-energy-up 2026-04-07T22:23:57.656416987Z Conservation of energy Let's solve some questions vibhor exercise https://www.khanacademy.org/science/in-in-class9th-physics-india/in-in-work-energy/in-in-power/v/power-work-energy-physics-khan-academy 2020-06-23T07:22:40Z Power Let's explore the meaning of power (rate of doing work) in physics.  David SantoPietro video https://cdn.kastatic.org/googleusercontent/14DowYKTOUJriOj1nfocq89GIng2pdsZhrXMZlyVbf07ocCVuHQ0LFZFhE2lK6h23LrrQdYhmRnherhUeqpZvz-S Power Let's explore the meaning of power (rate of doing work) in physics.  https://cdn.kastatic.org/ka-youtube-converted/u5OJ--Zk0FQ.mp4/u5OJ--Zk0FQ.mp4 169 Work and Energy https://www.khanacademy.org/science/bridge-course-class-11th-physics/x4c0d503cda725c32:work-and-energy/x4c0d503cda725c32:potential-energy/e/relating-power-and-energy 2025-04-09T10:12:02.040424533Z Relating power and energy Let's solve some questions! vibhor exercise https://www.khanacademy.org/science/strengthened-shs-physics-1/x5eb5cea12d2cf683:kinematics/x5eb5cea12d2cf683:work-and-power/e/optional-more-questions-on-conservation-of-energy-and-power 2026-04-08T00:54:09.631945657Z More questions on Power Let's solve some questions! vibhor exercise