what is energy?

Question

I cannot figure it out. Energy can neither be destroyed, nor created, and can only be exchanged between two adjacent regions of space. I do not understand this concept. please i need help in understanding this.

Answer 1

energy is something measured in Joules

Answer 2

Simplest, yet possibly least helpful definition is that energy is the capacity to do work.

Energy cannot be created or destroyed, but can be transformed (changed to a different type of energy)

For example

When you throw a ball straight up in the air the ball starts moving up, this is kinetic energy as it goes higher it slows down, so it loses kinetic energy, but the energy is conserved (transformed) in the form of potential energy because it is higher above the ground than it previously was. At it's peak there will be an instant with no kinetic energy and all potential energy, as it falls the process is reversed and the potential energy is transformed back into kinetic energy.

In this example there are hundreds of other transformations of energy that can confuse you, but just focus on the energy associated with the ball to appreciate the laws of thermodynamics. The other transformations include, conversion of chemical energy in your muscles to create a muscle contraction that moves your arm to throw the ball, the ball also has some friction or drag against the air which it moves through, then when you catch the ball you stop its kinetic energy which then is transformed into your body and makes a noise (kinectic energy in the sound waves this is an example of exchange to an adjacent region of space) etc. etc. etc.


Hope that helps

Answer 3

Think of it this way. Energy is a property of the universe we live in. Much like space is. Space cannot be created or destroyed either, at least not without destroying or creating more universe. The amount of energy (and it's converted form- matter) is, as far as we can tell, fixed.

You might also take it as akin to other things you know about the universe. While you can chop an onion up mighty fine, even liquefy it, you can't destroy whatever made up that onion. You can burn it to a crisp, but you are just shifting the atoms around from the combination that was 'onion' into a combination of what is now smoke, water vapor and ash.

The other thing is, that while it can't be created or destroyed, it sure as heck can be made unavailable to us. Just look at all the energy that goes out from the backside of the sun. We don't have a change of ever getting that.

Answer 4

Based on the Law of Conservation, matter of energy cannot be created nor destroyed. This is because the energy that is there is already in some kind of form. For example, an egg (out of its shell). When heat is applied to it, it changes form. The egg and heat is the energy because it is able to change phases.

Answer 5

to explain this, i will use the Law of Conservation of matter. The law says that matter cannot be destroyed or created just because it is put into another form (liquid, solid, and gas). the energy can be created, but when put into a different form it is not destroyed nor is more of it created. get it?

Answer 6

Energy is the capacity (or ability) to do work. That's probably the best definition I know.

That and remember that mass and evergy are really just two different forms of the same thing.

Doug

Answer 7

Thats the big echilada isnt it? If anyone really knew, you would have the Nobel Prize

Answer 8

Energy is the capacity or ability to do work. any other questions about definitions go to dictionary.com

Answer 9

energy is everthing knetic or not