If you’ve ever had any form of formal education (or at least a high school physics class), then you have probably heard the definition of energy as “the ability to do work”. This is actually a pretty good explanation for what energy is, but it doesn’t tell you much about how work itself is defined.
Basically, work is the product of force times displacement. The direction of the force isn’t important, and if the force is applied over a distance that does not change direction then the work done is zero. However, if the force is applied over a changing distance, then the amount of work done increases with the square of the distance and decreases with the radius of curvature of the trajectory.
The SI unit for work and energy is the joule.
A simple example of work being done is a horse pulling a plow through the field, or a teacher pushing on a book. The force caused the movement of the book, so work was done.
The more work that is done on an object, the greater its acceleration will be. This acceleration is a measure of the object’s kinetic energy, which is the energy it has due to its motion. It is also a measure of the total quantity of work that was done on the object, because the magnitude of the force times the magnitude of the displacement equals the sum of the product of the work and the time over which it was done.
In more complicated cases, the amount of work done on an object may depend on the direction and the magnitude of the force as well as its speed and other properties. For this type of motion, the work can be found by breaking up the movement into one-way and two-way one-dimensional segments and calculating the work over each segment. For an object moving in a circle, the work can be found by doing the following:
People’s work is a key determinant of their health and well-being. Every day, whether it’s a mother who works through lunch, the salesperson who answers emails after hours, or the technician who forgoes exercise to help a client, workers make trade-offs that affect their physical and mental health. To better understand how work impacts health, it is necessary to collect work-related data on a regular basis. This starts with including employment status, occupation, and industry in all survey and case studies, and expands to include data on other aspects of work that are important for determining health outcomes. Please contact us if you would like to learn more about incorporating data collection on work as part of your efforts to understand the link between health and the workplace. We’re happy to share our experiences and provide guidance. Thanks!
