Work is defined as the energy that is shifted to or from an entity by exerting force along with a displacement.

To answer the question “what is work?” simply…

Work is a physics term describing the amount of energy transferred whenever an object is displaced across a length by an externally applied force, with a component of which is applied in the displacement direction. 

Work is frequently expressed as the result of displacement and force in its basic form. When a force is applied, it is stated to do positive work when it is heading in the direction of the displacement of the site of application. If a force has a component that is going away from the direction of displacement at the site of application, it causes negative work.

Work completed on an object equals an increase in the object’s energy because work delivers energy to it. If the force that is applied is in opposition to the object’s motion, the work is regarded as negative, indicating that energy is withdrawn off the object.

Work is a scalar quantity, which means that it has simply a magnitude and no direction whatsoever. Work is the process of transferring energy from one location to another or from one type to another. There is no work performed until the entity is displaced in any manner and force is applied along the direction the entity is moved.  For example, simply holding an object motionless will not impart energy to it, because no displacement takes place.  

What is Work Done Mathematically?

Work can be calculated by multiplying the path length by the component of the force occurring down the path if the force is said to be constant. To demonstrate this concept numerically, the work, taken as W, is equivalent to the force, taken as f, times the distance, taken as d, so, W = fd. The work performed is W = fd cos θ if the force is applied at an angle of θ to the displacement. Work done on an object is achieved not only through moving the body or displacement as a whole from a location to the other but also by utilising an outside magnetic force.

The quantitative expression for work is varied by the certain circumstances that prevail. The work done while compressing gas at a constant degree can be represented as the product of pressure, which is P, and volume change, which is dV, hence, W = PdV.

What is Work’s SI Unit?

The SI unit for work is said to be the joule (J) which is the unit for energy as well, named after the 19th-century English physicist James Prescott Joule. It is expressed as the work necessary to apply a force of 1 newton over a 1 metre displacement.

The dimensionally equivalent newton-metre (Nm) is also at times used as a unit of work measurement; however, this should not be confused with the torque measurement unit, which people do quite often.  The SI authority recommends not to use the Nm because it can cause confusion as to whether a measure stated in newton metres is a measurement of torque or a work measurement.

The newton-metre, erg, foot-pound, foot-poundal, kilowatt hour, litre-atmosphere, and horsepower-hour are all non-SI units of work.

In Physics, What is Work’s History?

The old Greek theory of physics was confined to the statics (branch of mechanics) of simple machines (the balancing of forces), with no consideration of dynamics or the conception of work. The dynamics of the Mechanical Powers, as the rudimentary machines were known during the Renaissance, came to be investigated from the aspect as to how much they could raise a load as well as the force they were able to apply, ultimately resulting in the new idea of mechanical work. 

Galileo Galilei, the Italian scientist, developed the comprehensive dynamic theory of basic machines in his book Le Meccaniche (On Mechanics) in 1600, wherein he demonstrated the machines’ fundamental mathematical resemblance as force boosters. Galileo Galilei was the first one to point out that basic machines do not produce energy, but rather transform it.

As per Jammer, the French mathematician Gaspard-Gustave Coriolis first used the term “work” in 1826 to describe the lifting of water buckets out of waterlogged ore mines by early steam engines. As per Rene Dugas, a French engineer and historian, the term work as used in mechanics now, is owed to “Solomon of Caux”. 

Even though the term “work” was not used in a formal way until 1826, similar conceptions occurred before that time. John Smeaton used the term “power” in 1759 to define a quantity that signified the application of strength, gravitation, impulse or pressure, as to cause a motion.

Conclusion

In this article, you learn what is work, the SI unit for work and the history of work in physics. Work played an important role in shaping the history of physics, mechanics, power and energy. It is a core knowledge that is required in all science fields to get a better understanding of the fundamentals. 

Without the work and efforts of scientists and physicists like Galileo Galilei, James Prescott Joule, Newton etc., science and physics would not have come so far.