Work — and the ways in which we engage with it – have the potential to change the world. It can provide us with discipline, wisdom, skill and relationships that shape the course of our lives. It can help us feel accomplished and rewarded, even as it often drains our time, energy and passions. Whether we have fond memories of the mentors who taught us, the positions that stretched our limits, or the times it has jaded us and made us cynical, the way we use our bodies, minds, energies at work shapes our identities.
But work can also create problems, especially for frontline employees. This is why redefining work has become such a major focus of thought leadership and debate. To do this, we must first understand what it is and why it matters.
The scientific definition of work is: “The amount of energy transferred from one place to another or from one form to another.” The SI unit for work is the joule (J), which is equal to a force of 1 newton applied over a displacement of 1 meter. In everyday life, we rarely think about the process of doing work – the horse pulling a plow through the field, a parent pushing a shopping cart through the supermarket, a freshman lifting a heavy bag over her head, an Olympian throwing a shot-put. But these examples are actually a good example of work, because they have three key ingredients: force, displacement and cause.
For complex systems that undergo motion that is not one-way or in two or three dimensions, it is necessary to divide the motion into a series of one-way, one-dimensional segments and find the small amount of work done over each segment. This is done by solving an integral equation that takes into account both the force and the velocity of the system over time dt. The result is the area under the curve of the force vs. displacement graph.
The important thing to remember is that this definition of work applies to any system with momentum, not just a physical body. That is why we use a variety of measurement units for work, including the joule and the erg. Sometimes, we even use units typically reserved for heat or energy content, such as the calorie and the kilocalorie.
In general, the formula for finding the work of a system is dW = Fs dt. This is a path integral. To do the same work in two consecutive time intervals, we double the amount of force and then double the distance traveled. For example, it would take twice as much work to lift a weight of 100 pounds over the head as it did to raise it 50 yards. The same principle is true when we are analyzing an angular motion, such as the rotation of a shaft or the compression or rotary motion of internal particles in a mechanical system. This is why we speak of the “work of a system” when discussing angular motion, rather than simply “work.” The term is more accurate in this case because it includes all of the work that must be done to cause the movement.