Sometime in school, we study that Energy is the ability to do Work by a body or an agent. When an agent does work by applying a force, it is said that the amount of energy equal to work will be transferred to the body on which work is done. Whenever work is done, transfer of energy takes place.
The body which supplies energy is considered the agent which is doing work and its work is taken positive. And another body on which work is done gains energy and its work is taken negative.
Calculation of Work : By the fundamental method studied in early grades we calculate work by product of force and displacement of point of application of force.
See this video on work and its calculation – https://youtu.be/WEriI0hK0lc
Sometimes applied force varies with position of body then to understand how to calculate work by a variable force see this video – https://youtu.be/5fenCV_tUHw
Always remember that no matter how logical and advance the problem is, we will use always the fundamental way to calculate the work.
Many times students feel for advance problem there are some advance ways for work calculations. In further study we will see some more cases but the fundamental method explained above will always be applicable.
See below examples on work calculations –
Ashish Arora is the Head of Academics at the Allen Career Institute, Jaipur, Rajasthan. He is also the Founder and Chief Mentor at the Physicsgalaxy.com. His passion for physics has inspired many IIT aspirants.