الطاقة الميكانيكية Mechanical Energy .. كتاب في سبيل موسوعة علمية .. الدكتور أحمد ذكي

Mechanical Energy

The matter of power, and the meaning of work, power, and energy that follows from it, all of this has not occupied the minds of people and given them serious attention until recent times, as we mentioned.

Perhaps their work with it began during the era of the Italian researcher
Galileo in the sixteenth century, and he made his major leap by discovering the motive power of water vapor, by discovering the steam engine around the year 1760.

With the multiplicity of machines and the differences in engines, it became inevitable that all meanings related to movement were created in such a way that they are suitable not only for accuracy of understanding when communicating, but also for accuracy of numbers when calculating.

All of the first manifestations of energy were related to movement, so they were called kinetic energy.

But it has also appeared that this energy may be possible and benefit from it, but there is an obstacle preventing it from doing so. Example: A stone on top of a mountain. If it fell, it would gain strength and energy through gravity. But that is prohibited because he is on top of a mountain.

Likewise, the string that pushes the arrow: you pull it, storing potential energy in it, but it does not appear until you let it go.
Likewise, a clock spring is stretched to itself (full).
There is trapped energy that wants to be released.

This type of energy is called potential energy.

The two types end with movement, which is the huge meaning that emerged from the meaning of machine at the dawn of the present industrial age, so the name of these two types of energy was Mechanical Energy.


Mechanics is a word derived from a Greek word meaning machine. If we had called this mechanical energy, mechanical energy, we would not be far removed.

Heat, like movement, is energy:

The study of energy focused in the sixteenth century, and the centuries that followed, as we previously mentioned, focused on energy that creates work through movement. I mean mechanical energy, both apparent and latent.

Turning your attention to temperature, what is it? What is it like? Scientists conducted experiments that showed that energy
Mobility, when it appears to be destroyed, is in fact not destroyed, but is transformed into heat.

Count Rumford (175-1814 AD) was hollowing out a cannon barrel that he was making in a military factory. The amount of heat resulting from the movement of the drilling tool. He began examining, collecting, counting, and calculating, and he began comparing this with similar ones, and concluded that this heat only came out from this movement.

After Rumford came Sir Humphrey Davy (1778 - 1829 AD), the famous English scientist. He did the same thing on two pieces of ice. Move one piece above the other piece. The result is heat that turns the ice into water.

And you, yes you, when you move one palm over another: the palms become irritated. It is movement that generates heat.

Womford's experiments, Duffy's experiments, and others proved that heat arises from movement. So, in terms of nature, they are the same. They are two energies, different in appearance, but true in relation.

Despite this, doubt remained in the heart.
This suspicion was disappearing, or they also proved that
One amount of kinetic energy always produces a fixed amount of thermal energy.

(A whisk mixes the egg yolk with the albumen. It is moved by a hand. In the bowl there is a thermometer that records the temperature to which the mixture rises, that heat resulting from the conversion of kinetic energy into it, that is, into thermal energy. As for the origin of the movement, it is from the muscles of the hand and forearm, and this is from chemical energy. It results from the combustion of food in the cells of the woman’s forearm that moves the whisk.

This proof remained awaited by the English physicist Joule (1818-1889), who proved that a single amount of motion, if all of it is transformed into heat, produces an amount equivalent to the amount of motion. Therefore, movement and heat are matched in terms of transformation qualitatively and quantitatively. Nothing turns into something unless it is of one nature.

Heat is therefore energy that creates work, just like movement. Heat is also transformed into movement. Isn't it a force?
The steam locomotive, which is a driving force, originated from heat?! And you did useful work.

The tongue slipped and he said, “A useful job.” And what a mistake
Scientists differentiate between useful “work” that results from energy, and useless “work.” If this example that we mentioned is useful work, then the heat that resulted from the bore of the barrel of Count Rumford’s cannon is energy: it created (useless work). Heat wasted in the air and no one benefited from it.

- Electricity is energy:

In the same way, the scientist Joule proved, in 1840, that heat is energy, and he proved that electric current. What runs through a wire, and does no work of any kind, is transformed into heat, the amount of which is a fixed ratio to the amount of electricity consumed.

Other types of energy:

An example is light, which is produced from electricity
Similar natures. The conversion rate between them is fixed.

Chemical energy, such as the ignition of a stick of wood. Wood material is transformed by combining with oxygen in the air into materials with a simpler structure, and thus its chemical energy is transformed into thermal energy and light energy.

Chemical energy is one of the oldest energies that man used on this earth when he discovered fire.

And let us not forget nuclear energy, the energy of the atomic bomb,
In it, the nucleus of the atom is split and various types of energy are produced.
There are many other forms of energies that are similar to the ones we mentioned, and the ones we mentioned are the most important and most dangerous.

- Energy does not disappear:

The art is to say that matter does not exist. And if it appears to us
It does not exist, it changes from something visible to something hidden.

Like the wood fire we mentioned, nothing remains of it that can be seen after the fire except ash, and most of it turns into gases that go into the atmosphere. We do not see them, but they are there. There is no doubt about this.
And also energy.
We return to the wood fire again. It is chemical energy converted into calculated thermal energy. Then she disappeared, where did she go? Did it not exist? The answer: No. Energy, like matter, does not exist. Rather, it spreads into the air surrounding it, increasing the movement of its gas molecules. It is there in the form of kinetic energy distributed among the air molecules.

- This universe:

Matter and energy
Body and soul...,
This universe, despite the enormity of its bodies and the distance of its edges (if it has a side to mention in a conversation), has two aspects:
material
And energy
A duality like the duality of man and animal.

(The universe, which contains as many stars as sand, and as many suns as it contains a thousand suns, is nothing but matter absorbed by energy, just as bodies are absorbed by souls.)

body
And spirit...
If you wish, you can say that cosmic matter is a body and its energy
Her soul.
Energy is like the soul.
She doesn't see.
It does not weigh.
And it doesn't taste.
Rather, it impersonates things and things are perceived by the eyes.
Energy cannot be perceived by sight.

This small rolling ball, I see it moving, and I say it has movement, but if you ask me what movement is, it is as if you asked me what the soul is. Her knowledge is with my Lord.

And this star, or rather these stars, or even these galaxies, follow enormous paths in the universe, driven by energy, or rather energies, whose effects we feel visually, but we do not perceive them in substance.

Like movement, heat.
Who among us has seen heat? Who among us has weighed heat and made it heavier or lighter on a scale, just as bodies become heavier and lighter?

Like heat, light.
Like movement, heat, light, and all other types of energies.
This world, if any matter has been embodied in it, then all this matter has energies dominated.

Energies are the first and last engine, and they are the interior of all these phenomena. They are the souls of all these bodies.