Work can be a source of pride, a source of fulfillment and a source of self-esteem. But, work can also be a source of anxiety and stress. If you find yourself feeling anxious about work, it may be time to take a step back and examine the way in which you think about your job.
In everyday use, the word “work” refers to any activity requiring effort or exertion – whether mental or physical. Work can also refer to any purposeful activity aimed at earning one’s living. Other words for work include labor, travail, toil, drudgery and grind. The concept of work has also been extended to activities performed by machines and natural forces.
A force acting on an object can do work by moving the object a specified distance in a specific direction. The amount of work done is the product of the magnitude of the force and the displacement – expressed in units of energy called joules (J).
The direction of the displacement determines if the work is positive, negative or zero. For example, if the force on the object is perpendicular to its direction of displacement – as when a friction force acts on an object in the forward direction – the work is negative. If the force on the object is parallel to the direction of displacement – as when gravity pulls a body toward the center of the Earth – the work is positive.
Sometimes, a force acts upon an object to hinder its motion rather than cause it to move. Examples include a car skidding to a stop on the roadway surface and a baseball runner sliding to a stop on the infield dirt. The amount of this type of work is negative.
In physics, the concept of work can be applied to non-mechanical systems as well. For instance, a magnetic field can do work on a particle by causing it to change its direction of motion or by changing the speed of the particle. This type of work is also negative. Work can be accomplished in other ways as well, such as compressing a gas or rotating a shaft. All of these types of work can be measured and are also expressed in joules (J).