Work, Energy and Power Explained: Why Holding a Suitcase Is No Work | Physics Explained 9.1

Hold a heavy suitcase for an hour and a physicist says you did no work on it. This lesson explains what work really means (W = Fd, in joules, with the force along the motion), then connects work to energy: kinetic energy ½mv² and potential energy mgh. Worked examples: a weightlifter's 400 J, the work-energy theorem for a pushed skater (2000 J, and why it isn't 400 J), power P = W/t with two ways to carry a TV up four floors (20 W vs 8.2 W), horsepower and kilowatt-hours, and how long it takes to push a sled to 3.2 m/s at 18 W. Chapters: 0:00 Intro 0:56 Work: force times distance 1:57 Worked example: the weightlifter 2:25 Energy: the ability to do work 3:36 The work–energy theorem 4:11 Worked example: a push on the ice 5:07 Power: how fast work is done 6:26 Worked example: pushing a sled 7:11 Common mistakes 7:42 Recap 8:21 Check yourself 9:31 Up next Physics Explained, Chapter 9: Work, Energy, and Simple Machines (lesson 1 of 3) Adapted from Physics by OpenStax (https://openstax.org/details/books/ph..., licensed under CC BY 4.0 (https://creativecommons.org/licenses/.... The animations and narration are original to Prime Mover. OpenStax is not affiliated with this channel and does not endorse it. Prime Mover: learn it, build it, share it.