Energy Transformations – Fundamentals of Engineering Module #7

conservation of energy principleWe’ve all been waiting for it.  Maybe you thought the principles of energy below were going to come out with Newton’s Laws earlier.  You’ve heard them before, maybe in like sci-fi thrillers where the entire world was going to end or a mad scientist was trying to devise something so sinister.

This quick post is going to be about the principles of energy transformations – the conservation of energy and the conservation of matter.

How does this apply out in the world?

Systems are designed either to carry energy from one place to another or to change a substance from one form to another.  As you know, systems are everywhere surrounding us.  Hello Terminators.  Your home has a thousand systems (furnace, plumbing, maybe not 1000,) your car (fuel, exhaust, heat,) buildings for the building engineers reading this.

Conservation of Energy

law of conservation of energy

An example of a principle.

The basic principle dealing with the transformation of energy is the principle of the conservation of energy.  Gripping sentence right?  This principle can be stated in several ways.   Several really cool, intriguing ways if you really, really sit back and think about the magnitude of them.

Most commonly probably, it is stated that energy can be neither destroyed nor created, but only transformed.

That’s the mad scientist way to say it that we all know and can recite right?

Another way to state this principle is that the total quantity of energy in the universe is always the same.  Even another way of expressing this principle is by the simple equation, energy in = energy out.  These are the crazy if you truly think about them ones.

The energy out may be quite different in form from the energy in, but the total amount of energy input must always equal the total amount of energy output.  Somewhere, somehow.  Everything will always be trying to level out.  Trippy.

The Brother from another Mother Principle

The other principle, the principle of the conservation of matter, states that matter can be neither created nor destroyed, but only transformed.

The development of bombs way back (like the race in the 40’s) showed that matter can be converted into energy.  Other experiments and developments have demonstrated that energy can be converted into matter.

So now it is accepted that:

  • the principle of the conservation of energy and the principle of the conservation of matter are no longer considered as two parts of a single law or principle but are combined into one.  A superhero.

That principle states that matter and energy are interchangeable, and the total amount of energy and matter in the universe is constant.

The interchangeability of matter and energy is mentioned here only to point out that the statement energy in must equal energy out is not strictly true for certain situations.  However, any noticeable conversion of matter into energy or energy into matter can occur only under very special conditions.  Of which, I do not know, I wouldn’t even know where to begin.

All the energy transformations that we will deal with as building engineers, nuclear sailors, even homeowners or curious readers, can be understood quite simply if we consider only the principle of the conservation of energy, energy in = energy out.

Click here for lesson #8 in fundamentals – getting heat to do work for us.

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