# Action (physics)

In physics, action is a scalar quantity describing how a physical system has changed over time. Action is significant because the equations of motion of the system can be derived through the principle of stationary action. In the simple case of a single particle moving with a constant velocity (uniform linear motion), the action is the momentum of the particle times the distance it moves, added up along its path; equivalently, action is twice the particle's kinetic energy times the duration for which it has that amount of energy. For more complicated systems, all such quantities are combined. More formally, action is a mathematical functional which takes the trajectory (also called path or history) of the system as its argument and has a real number as its result. Generally, the action takes different values for different paths. Action has dimensions of energy × time or momentum × length, and its SI unit is joule-second (like the Planck constant h). (Wikipedia).

What is a force?

Describes what forces are and what they do. You can see a listing of all my videos at my website, http://www.stepbystepscience.com

From playlist Mechanics

A03 The equations of motion

The equations of motion

From playlist Physics ONE

A02 The equations of motion

The equations of motion

From playlist Physics ONE

A04 The equations of motion

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From playlist Physics ONE

What is Force? - Part 1| Forces and Motion | Physics | Don't Memorise

Most people think that Force is just a push or a pull upon an object. But is there anything more to it? What is a force? What are forces and motion (Physics Grade 9) Watch this video to know more about force. Here's the second part of the Force concept - https://www.youtube.com/watch?v=i

From playlist Physics

Physics 9.5 Introduction to Momentum (6 of 9) What is Impulse?

Visit http://ilectureonline.com for more math and science lectures! In this video I will explain what is impulse and how is it related to momentum. Next video in this series can be seen at: https://youtu.be/Deog-gun7OA

Action and Reaction: Newton’s Third Law

Newton’s third law is about action and reaction. It applies to motion on every scale–from a person jumping or swimming, to a rocket launching into space.  To learn more, check out the free tutorial on our website: https://edu.gcfglobal.org/en/newtons-laws-of-motion/ #newton #physics #m

From playlist Newton's Laws of Motion

Physics 10 Momentum and Impulse (1 of 30) What is the Definition of Impulse?

Visit http://ilectureonline.com for more math and science lectures! This four part lecture series will cover momentum and impulse. How quickly a force is imparted onto an object makes a big difference!

A06 The equations of motion

A mathematics bonus. In this lecture I remind you of a way to calculate the cross product of two vector using the determinant of a matrix along the first row of unit vectors.

From playlist Physics ONE

SkFun: SpriteKit And RubyMotion

By, Will Raxworthy Help us caption & translate this video! http://amara.org/v/FGZ2/

From playlist Inspect 2014

Minds, Brains, & Science - John Searle (1984 Reith Lectures)

In this series of lectures, John Searle, former Professor of Philosophy at Berkeley, examines the connections between minds, brains, and science. These lectures were given as part of the 1984 BBC Reith Lectures, but are still just as relevant today. Some of the topics discussed include fre

From playlist Philosophy of Mind

Physics in 10 minutes - The principle of least action

This is my contribution to the summer of math exposition #SoME1 The viewer is introduced to the fundamental principle of least action that can be found all over in classical physics. It also provides the starting point for modern approaches to quantum physics. The topic is introduces on

From playlist Summer of Math Exposition Youtube Videos

Lagrangian Mechanics - A beautiful way to look at the world

Sign up to brilliant.org with this link to receive a 20% discount! https://brilliant.org/upandatom/ Lagrangian mechanics and the principle of least action. Kinematics. Hi! I'm Jade. Subscribe to Up and Atom for physics, math and computer science videos! *SUBSCRIBE TO UP AND ATOM* http

From playlist Physics

Nathan Seiberg - Quantum Field Theory of Exotic Systems - IPAM at UCLA

Recorded 30 August 2021. Nathan Seiberg of the Institute for Advanced Study presents "Quantum Field Theory of Exotic Systems" at IPAM's Graduate Summer School: Mathematics of Topological Phases of Matter. This is the first of Nathan's two presentations. Abstract: Until recently, it was wid

Explaining the Principle of Least Action: Physics Mini Lesson

The principle of least action is a different way of looking at physics that has applications to everything from Newtonian mechanics, to relativity, quantum mechanics, and beyond. Get the notes for free here: https://courses.physicswithelliot.com/notes-sign-up Take my full course on Lagran

From playlist Hamiltonian Mechanics Sequence

Studying thermal QCD matter on the lattice (LQCD1 - Lecture 2) by Peter Petreczky

PROGRAM THE MYRIAD COLORFUL WAYS OF UNDERSTANDING EXTREME QCD MATTER ORGANIZERS: Ayan Mukhopadhyay, Sayantan Sharma and Ravindran V DATE: 01 April 2019 to 17 April 2019 VENUE: Ramanujan Lecture Hall, ICTS Bangalore Strongly interacting phases of QCD matter at extreme temperature and

Displaced Searches New Physics at Belle by Sabyasachi Chakrabarty

DISCUSSION MEETING PARTICLE PHYSICS: PHENOMENA, PUZZLES, PROMISES ORGANIZERS: Amol Dighe, Rick S Gupta, Sreerup Raychaudhuri and Tuhin S Roy, Department of Theoretical Physics, TIFR, India DATE & TIME: 21 November 2022 to 23 November 2022 VENUE: Ramanujan Lecture Hall and Online While t

G actions in SUSY QM; or, the Fukaya category of point/G by Tudor Dimofte

Program: Quantum Fields, Geometry and Representation Theory ORGANIZERS : Aswin Balasubramanian, Saurav Bhaumik, Indranil Biswas, Abhijit Gadde, Rajesh Gopakumar and Mahan Mj DATE & TIME : 16 July 2018 to 27 July 2018 VENUE : Madhava Lecture Hall, ICTS, Bangalore The power of symmetries

From playlist Quantum Fields, Geometry and Representation Theory

Physical Science 2.1a - Force

Force. Definition, examples, and the idea that force is a vector.

From playlist Physical Science Chapter 2 (Complete chapter)

Lecture 3 | Modern Physics: Classical Mechanics (Stanford)

Lecture 3 of Leonard Susskind's Modern Physics course concentrating on Classical Mechanics. Recorded October 29, 2007 at Stanford University. This Stanford Continuing Studies course is the first of a six-quarter sequence of classes exploring the essential theoretical foundations of mod

From playlist Course | Modern Physics: Classical Mechanics