Energy


 * Energy** is the capacity to do work or supply heat.
 * Work** is done when movement occurs against a restraining force
 * Power** is work per unit time
 * Heath** is energy that flows from a hotter to a colder object
 * Temperature** tells us the direction of heat flow

One **joule** (J) is the work done by a force of one Newton (N) acting through a distance of one meter

One **Newton** is the force required to cause a mass of one kilogram to accelerate at a rate of one meter per second squared in the absence of other force-producing effects

One **calorie** is about the amount of heat needed to raise the temperature of one gram of water by 1 degree Celsius 1 calorie = 4.184 J 1000 calories = 1 Calorie 1 Calorie = 1 kcal 1 kcal = 1.16 watt hr

Types of energy:
 * Potential**: stored energy/energy of position
 * Kinetic:** energy of motion

Forms of energy:
 * Mechanical
 * Radiant
 * Electrical
 * Chemical
 * Nuclear


 * 1st law of thermodynamics:** Energy is neither created nor destroyed (but we can transform it)

All energy conversions suffer from inefficiencies.
 * 2nd law of thermodynamics:** Entropy always increases (limits efficiency of heat-driven processes)

Energy transformation process: Potential energy (fuel molecules) > Kinetic energy> Mechanical energy > electrical energy