#### Transcript of Law of Conservation of Energy

**The Law of Conservation of Energy**

The law states that energy cannot be

created

or

destroyed

. Energy can only change

forms

.

What is the Conservation of Energy?

So what does this mean?

All energy(ies) are measured in joules, and the

total

number of joules of energy in a closed system always remains the same.

This means that regardless of how many transformations energy goes through the total number of joules in the system will not change.

So, how is energy conserved?

Changes in energy or energy transformations can only take place in a

closed system

A closed system is a group of objects that transfer energy only to

each other

.

'Get the ball rolling' example

roll a ball across carpet and watch what happens.

Why doesn't the ball keep rolling?

The kinetic energy of the ball transforms into

thermal

energy in the

rug

and

air

.

So, lets talk about an example.

Other examples of energy transformations are...

Example

When energy is turned into useful energy, but some energy is always transformed into an unintended form.

The most common unintended form is Heat.

Energy EFFICIENCY is a comparison of the amount of energy

before

a conversion with the amount of

useful

energy after a conversion.

Efficiency

Some examples of energy efficiency are cars and the home you live in.

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