Mechanical work requires a force capable of altering the state of motion of a body.
Work is a notion with multiple meanings. In this case, we are interested in its meaning linked to the product of a force . Mechanic , on the other hand, is a term that is related to the branch of physics that focuses on the movement and balance of objects that are subject to the influence of a force.
Mechanical work is the work developed by a force when it manages to modify the state of motion of an object. Mechanical work is therefore equivalent to the energy needed to move the object in question .
Physical magnitude and equation
In this context, mechanical work can be understood as a scalar physical magnitude , which is expressed by the unit of energy known as the joule . Whenever a force is applied to a body and displaces it, it performs mechanical work that can be measured in joules.
When mechanical work (symbolized by the letter W , from the English term “work” ) is expressed through an equation, it is said that W is equal to the force applied times the distance traveled. This is because mechanical work assumes that the force is applied in a certain path.
Example of mechanical work
A simple example of mechanical work is when a worker pushes a wheelbarrow loaded with bricks from one section of a construction site to another. The person applies a force to move the wheelbarrow: therefore, mechanical work is performed.
The application of this force continues until the man stops pushing the wheelbarrow; once he stops pushing (i.e., performing mechanical work), the wheelbarrow stops.
When a person pushes a wheelbarrow full of bricks, he performs mechanical work.
Classification according to type
It is also important to know that the work we are dealing with, if we take into consideration both the displacement it undertakes and the force and angle it generates, can be classified into several types:
-Negative or resistant work, which would be, for example, the work of the friction force and which is expressed by W0. A clear example of this type is the work performed by an ox pulling a plough.
-Zero work, which could be the work performed by any person, in terms of force and weight, when driving a car. It is expressed as follows: W=0.
When we talk about mechanical work, it is common to choose to mention two other types of work that exist and are especially used in the field of Physics, in order to understand the world around us. We are referring specifically to these:
-Electrical work, which, as its name indicates, refers to the set of charges and their movement within a specific electric field.
-Thermodynamic work. This refers to the set of changes that bodies experience in terms of their volumes when they are subjected to different pressures or when they are subjected to different temperatures.