1. What is Energy? Physics Definition: The ability to do work
Work: Force applied over a distance (W =f*d)
Force: From Newton, force is the product of a mass and its acceleration (F=ma) also known as Newton’s second law.
But this applies mostly to mechanics, the study of the physics behind an object’s motion

2. What is Energy?
Thermodynamics: the study of the conversion of heat energy into other forms of energy.
Very important in the production of energy as we will discuss it
In themodynamics, work is defined as the quantity of energy transferred from one system to another without a change in its amount of order (called entropy)

3. Units of energy Joules:
The work done by a force of one newton (kg*m/s2)traveling through a distance of one meter;
The work required to move an electric charge of one coulomb through an electrical potential difference of one volt; or one coulomb volt, with the symbol C·V;
The work done to produce power of one watt continuously for one second; or one watt-second (compare kilowatt-hour), with the symbol W·s. Thus a kilowatt-hour is 3,600,000 joules or 3.6 megajoules;
The kinetic energy of a 2 kg mass moving at a velocity of 1 m/s. The kinetic energy is linear in the mass but quadratic in the velocity, being given by E = ½mv²

4. Everyday examples of the Joule
the energy required to lift a small apple one meter straight up.
the energy released when that same apple falls one meter to the ground.
the energy released as heat by a quiet person, every hundredth of a second.
the energy required to heat one gram of dry, cool air by 1 degree Celsius.
one hundredth of the energy a person can receive by drinking a drop of beer.
the kinetic energy of an adult human moving a distance of about a hand-span every second.
100 joules are used by a 100 Watt light bulb every second

5. Power Power: the rate at which work is performed P=E/t
Or, the rate at which energy is transmitted
Or the amount of energy expended per unit time
P=E/t
Measured in Watts:
Other units:
HP or horse power
BTUs