Work and Force

Dynamics and its studies were not included during ancient Greek physics as it was only limited to working of simple machines. During the Renaissance mechanical work and its concepts were developed. It looked after the simple machines and their capabilities to lift loads along with the force they needed to be applied for doing that act. 

In 1600 Galileo Galilei first discovered the dynamic theory of simple machines. It showed how simple machines help us in multiplying and amplifying the forces we apply. It was first said by Galileo that, rather than creating own energy the machine just enhances the energy we put and transforms it. 

What is Work done ? 

Work done is a scalar quantity because it has its own magnitude but it has no direction of its own. Work is a medium to transfer energy from a place to another and it also results in changing the energy from a form to another. Work done can be measured and the SI unit of measurement for work down is , joule(J). The unit of work done is the same for energy too. 

History of work done 

It was 1826 when “work” was first used as a term . Gaspard-Gustave Coriolis defined work done as weight lifted through a height. The definition was based on the use of steam engines , used back in the day for elevating the water buckets out of ore mines during floods. 

Before the formal use of the word work was not done until 1826 but it never stopped scientists from making similar claims. John Smeaton had named a new quantity as “power” , according to him it was the weight raised multiplied by the height of its upraise on a fixed time period. The main thing was that these claims were nothing very different than the ones of Coriolis. 

Units of work done 

We know, the SI unit of work done is joules (J). The unit is defined as work required to be done for using a force of 1 Newton for a displacement of 1 metre . The naming is based on James Prescott Joule. 

Newton-metre is also an unit that is used  sometimes for measuring work done. However it is not widely accepted as N⋅m is used for calculating torque and it leads to confusion of expression. 

There are some of the non-SI-units of work done too, erg, newton metre, foot-pound, kilowatt hour, horsepower-hour etc. Apart from these some units which are strictly related to heat energy and work done are therm, BTU and calorie. 

Work done formula 

The work done formula is :-

W=F * d

Here W is used for denoting the work done which would be calculated, F used for denoting the force required to be put in for moving the body for a fixed displacement. The d here denotes the displacement the body has after the application of force on it  . 

Examples 

A ball which is held at a point elevated from the ground is dropped, then the work done by the gravitational force of the earth is equal to the weight of the ball which is the force applied in this case of gravitational pull multiplied with the distance till the ground. The distance till the ground is the displacement in this case. 

A cricket bowler applies force on the ball by throwing it with force and it travels a distance still the batsman . 

Conclusion

The calculation of work was one of the major scientific findings which helps us in knowing the force we require completing a particular task. The work done can easily be calculated now by multiplying the force applied with the displacement that occurred after its application.