Work is anything that requires physical or mental effort, including learning, playing music, writing an essay, preparing for a test, and cleaning the house. Often, work involves earning money for performing a service or producing a product. Some people enjoy their jobs because they feel productive and important, while others struggle with the demands of work and its consequences for their health. This article explains what work is, how it is measured, and some of the benefits and costs of working.
The word “work” is derived from the Latin word oratio, meaning “to try or exert.” For many people, work is an integral part of their lives and contributes to a sense of self-worth. The work that people do is a way to fulfill their needs and aspirations, connect with others, and make a difference in the world. Moreover, work is a way for employees to create value for the company they work for and themselves. Consequently, employees who enjoy their jobs and find meaning in them are more likely to be engaged and productive at work.
Despite the common perception that work is only done by a select group of professionals, everyone performs some form of work in their daily life. Examples of work include a teacher pushing against a wall and becoming exhausted, a baseball player throwing a ball, a traveller pushing their luggage from the airport to their hotel room, a mechanic repairing a car, a baker baking bread, or a cobbler polishing shoes. These activities involve the application of force to an object resulting in its movement or change in position.
A more formal definition of work in physics is the scalar product of a force F and its displacement or change in position D, which is equal to the product of the force strength and the distance traveled. Work is a vector quantity because both the direction of the force and the direction of the displacement have an associated magnitude, so that integrating the scalar product over the trajectory of the point of application C of the force leads to the formula for work.
An important consideration when calculating work is that the direction of the force must be perpendicular to the direction of the displacement. Otherwise, no work is performed. For example, a person pushing against a wall and getting tired is not doing any work because the force is not aligned with the displacement. However, a book falling off a table and hitting the ground is doing work because the force (gravity) is in the same direction as the displacement (down).
An additional important point when calculating work is that the change in energy of the system has to be equal to or greater than the total work that was done on the system. For this reason, the SI unit for work is the joule (J). Therefore, lifting 100 lb one foot twice is the same as lifting it once and then moving it one foot.
