The term joule or July , is used in the field of physical to refer to a work unit It is part of the international system. A joule is equivalent to work that produces a constant force of a newton whose point of application travels one meter in the same direction of the force .
To understand what a joule is, therefore, it is important to know before what several concepts consist. In physics, the job It is the product of a force for the distance traveled by its point of application. In other words: when a force modifies the state of motion of a body, it performs a job.
A newton , meanwhile, is a unit of force. A Newton equals the force that manages to produce an acceleration of 1 meter / second every second when applied to a body With a kilogram of dough.
Combining the concepts of job , force and newton , then we come to the idea of joule, whose symbol is J . The formal definition indicates that a force of 1 Newton with an application point that moves one meter in the same direction of the force performs a workload of 1 joule .
It is essential to keep in mind that, for theoretical purposes, the various resistances are not considered. Therefore, when measuring the work of the force, the influence of the friction of the air , for example.
It should be noted that joule comes from James Prescott Joule . This English physicist, born in 1818 and died in 1889 , made great discoveries linked to the Energy , electricity, magnetism and thermodynamics.
When solving problems, it is very important to know the equivalences of the different units used, since many times it depends on this resource the possibility of clearing an unknown and finding out its value . In the case of joule, the list is quite extensive. We can say, therefore, that one joule equals: one newton per meter; one watt per second; 6.2415 by 10 raised to the 18th electron volt; a coulomb by volt; 0.00987 atmosphere per liter; one pascal per cubic meter; 0.238902957 calorie.
As we can see, there are many units that relate to the joule, and some are not so common outside the realm of physics. He electron volt , for example, is the unit of energy that serves to represent an energetic variation of kinetic type that crosses a electron when it moves between two points of different potentials (which are usually designated with Va and Vb), provided that the difference between them is one volt.
He coulomb On the other hand, it is a unit that derives from the international system and is used to measure the physical magnitude known as electric charge or amount of electricity. His name also derives from a physicist, this case from French Charles-Augustin de Coulomb . The definition of the coulomb is as follows: it is the amount of charge that a current of one amp carries in a second.
These equivalences are measured taking into account 1 joule, but there are also others that are called inverse, in which the value 1 has the others units . Let's look at some of them below: one watt per hour equals 3600 joules; one kilowatt per hour is equal to 3.6 by 10 raised to 6 joules; one calorie equals 4,187 joules; one kilocalorie, since it is a thousand calories, is equal to 4187 joules.
Physics also uses everyday examples to graph some of its concepts. In the case of a joule, it is estimated that it is: the energy used to throw a small apple up so that a subway ; the energy that is released when said apple falls.