Introduction
To any machine, work is a matter of principle, because everything a machine does is in accordance with a set principles or scientific laws.
Mechanical machines work with parts that move. These parts include levers, gears, belts wheels, cams, cranks, and springs, and they are often interconnected in complex links.
The lever
The simplest machine and perhaps the one with you are most familiar is the lever.
You will find that all levers have three basic parts; the fulcrum (F), a force of effort (E), and a resistance (R). Look figure 1.
Classes of levers
There are three different basic kinds of levers:
First class. The second class of lever has the fulcrum is located between the effort and the resistance. The amount of weight and the distance from the fulcrum can be varied to suit the need. Figure 2.
Second class. The second class of lever has the fulcrum at one end, the effort resistance somewhere between those points. Figure 3.
Third class. Something you will want to speed up the moment of the resistance ever, though you have to use a large amount of effort. Level, that help you accomplish this are in the third class of lever.
The wheel and axle
The wheel and axle can be used as a tool to multiply the force you apply, or to multiply the distance travelled. Here´s how it work…
You apply a force on the wheel, whose radius R is larger than the axle, which has radius r.
This resultant force, with is bigger than the force you applied does some work for you.
The force that does the work is bigger by a factor of R/r.
For example, if the wheel is ten times wider than the axle, the resultant force will be 10 times bigger. Wheel and axle machines of this form are very common.
My opinion
Machines help humans to do things more easily in his life.
In the books, I read that it would be impossible to imagine how we live now without the invention of machines, and I think after reading that is true because simple machines are the ones we use every day for work or fun.
I learning that our bodies are machines but also helped invent our brains are not as natural as the wheel.
I think machines are very interesting and now a lot more of them and I can talk about it with my family because I like machines and love to hear from them.