Physics is a natural science. Perhaps that is why she is given so much attention in the school course. Often students are faced with the question of what is measured in joules. This is quite expected, since different branches of physics may include this quantity. However, if you try to understand the topic a little, then everything will immediately fall into place. Where can you find something that is measured in joules? The answer is not simple, but understandable.
It all starts with the simple formula A=FS. A test paper can fall into such a dependence after the first month of acquaintance with physics. If you immediately understand what's what, then you can begin a completely successful acquaintance with science. F - the sum of all the acting forces applied to the body, which influenced the change in the position of the body. It is measured in newtons. The judgment that force is measured in joules is wrong. S is the path that the body has traveled. In SI units, it is denoted by meters. Thus, 1 J=1 N1 m. That is, in fact, we found work from a physical point of view. And it doesn't matter who and under what circumstances it was committed.
Further, as a rule, inthe eighth grade studies thermal processes. Many new concepts are introduced here. Basic formula: Q=cm(t1-t2). Here again the question arises of what is measured in joules in this relationship. And, by the way, we note that some strange variable c has arisen. In fact, this is the specific heat capacity of the substance. It should be noted that this, as a rule, is a constant value, measured for a long time. Its dimension: J / (KgDegrees Celsius). From here it is easy to see that it is worth multiplying this value by mass and by a certain temperature, then you get joules. That is the letter Q. It is measured in them. It is worth saying that in fact heat is energy. For example, in internal combustion engines, Q is first allocated, which then passes into A=FS with some efficiency. On this, in principle, some Olympiad problems for grades 7-8 can be based.
Another big section to look at in order to know what is measured in joules is "Electricity". Of course, in a more global framework it is called a little differently, but such a designation is also suitable for a school interpretation. Many people know on what principle incandescent lamps are based. Where does thermal energy come from? Yes, electric current does some work, which can be calculated using the formula A=IITt. Here t is time, I is current, R is resistance. Here work is also measured in joules.
One cannot but say about mechanics, in which the quantity under consideration has considerable application. Often in school tasks hasmeaning of the law of conservation of energy. So this energy is measured in Joules. The main meaning of the formulation of the law is that the body has some kind of energy during movement, thermal processes and other physical processes. And if, for example, a wooden block slides over the surface and stops, this does not mean that it is losing energy. It just goes to work the force of friction.
So you learned what is measured in joules. As you can see, this characteristic is used in many completely different branches of physics. However, if you understand the essence, it becomes much easier.
