March 31, 2025

What Is Work?

As long as it is well-paid, stable and safe, work provides many benefits, including a sense of purpose, identity, and self-worth. It is also a vehicle for social interaction, and an opportunity to contribute to the success of others. Moreover, it supports the economy and allows people to afford to live, eat, buy clothes, rent, travel, etc. Work also gives people a chance to meet like-minded individuals and develop their own unique talents, skills, and interests. However, for some, work can be a source of stress and anxiety. For example, lower-income workers are more likely to say they don’t have a good relationship with their employer and feel they do not receive recognition or rewards for their work.

In physics, “work” refers to the transformation of energy from one place to another. It is defined as the scalar product of force and displacement, where force is a vector and distance is a scalar. The unit of work is the joule, the same as that of energy. It can be applied to any object, irrespective of its mass or shape, and can cause changes in either the object’s kinetic or potential energy.

Work can be positive, negative, or zero, depending on the direction of displacement with respect to the force. For example, if an object is displaced perpendicular to the force that moves it, the work done by the force is zero. If an object is displaced parallel to the force that moves it, the work is positive. If an object is displaced at an angle with respect to the force that moves it, the work it does is negative.

For a body moving along a curve C with a velocity v, the small amount of work dW that occurs over an instant dt is calculated as int _Cmathbf F cdot v dt, where F dW is the power input to the system at the point of application of the force and dv is the displacement vector. This is the same as integrating the power of the force over the trajectory of the displacement, a process known as path integral.

Work can be measured in units such as newton-metres (Nm), erg, watt, and foot-poundal, but the SI unit for work is the joule. In practice, work is often defined as a function of time and is expressed in terms of an energy-time integral or a power-time integral. Work can also be derived by applying the same principles to non-linear systems, such as those that exhibit vibration or inertia. In these cases, a more complex form of the equation can be used, where the parameters of the system are not explicitly specified. However, this can lead to inaccuracies when the system is not properly modelled. For this reason, many engineers use the simpler formula above for most practical applications.