Introduction to Energy Introduction to Transportation

Objectives After completing this lecture, you will be able to: 1. State what Energy is 2. State the two types of energy 3. State the 6 different forms of energy and examples of each 4. State what the Law of Thermodynamics is 5. State what entropy is 6. State the three ways heat travels and explain each

Objectives 7. State what the differences between renewable, nonrenewable, and inexhaustible are 8. What is the history of human effort to shift the burden of work from human to machines 9. State the modern conversion systems

What is Energy? We all use energy but what is energy? Answer: Energy is the ability to do work. In order to get a complete understanding of what energy is, we need to understand what work is. Work is that which causes change. Work is that which involves change, support, or movement. Some examples are: the sun heats up the earth, wind blows trees, water moves down stream not up.

What is a Design Energy System? Since energy is all around us and made up of systems our entire world is made up of systems. Those systems are inputs, processes, outputs, and feedback. Inputs are defined as resources. The inputs are people, material, knowledge, capital (tools, buildings, equipment), finance, and time

What is a Design Energy System? Processes are the work required to give a value to what is produced. The processes are moving people or cargo Outputs are the new location of people and cargo. They are produced in terms of wanted and unintended outputs Feedback is any signal or information that might adjust the process or initiate it to improve the process

What are the two types of Energy? There are two types of energy and it usually used for motion classification. Potential Energy and Kinetic Energy What is Potential Energy? Answer: Potential Energy is energy that is waiting to do work. It is at rest, in storage, inactive

What are the two types of Energy? What is Kinetic Energy? Answer: Kinetic Energy is the ability of objects that are moving to do work. Any body in motion has kinetic energy

What are 6 forms of Energy? Light Energy- energy traveling through space as a wave motion. This energy travels through space and the earths atmosphere at 186,000 miles per second Heat (thermal) energy- energy that will cause the temperatures of objects to rise Mechanical Energy- energy dealing with both the work output and input of machines

What are 6 forms of Energy? Chemical Energy- usually stored energy that can be released as any of the other forms of energy (ex. A battery stores chemicals and releases it as electrical energy) Electrical Energy- when negatively charged particles are attracted to positively charged particles. Negative particles are called electrons and positive particles are protons.

What are 6 forms of Energy? Nuclear energy- released when certain types of atoms are split. The release can be swift as in the explosion of an atomic or hydrogen bomb or slowed to produce huge amounts of heat with a very small quantity of material.

What are the Laws of Thermodynamics? The Laws of Thermodynamics are: First, energy cannot be destroyed, it can be changed from one form to another but it will always exist Second, once energy is used it loses its ability to do work even though it is not destroyed.

What are the Laws of Thermodynamics? For example a person on a swing uses energy to pump the swing. Eventually the swing will stop when no more energy is put into making it continue to swing. Friction and wind resistance bring it to a stop.

What is Entropy? Answer: The principle of entropy is that eventually all energy, as it is used, becomes so scattered that is loses its ability to do work.

What is Entropy? Example, you boil water to power a small steam engine using a flame. Once you take the flame away the steam cools. The water is still hot but it lost its energy to power the engine.

Three Ways Heat Travels There are three ways heat travels and we all use some form of them everyday. Convection, Conduction, and Radiation Convection is movement of heat within liquids or gases. The heat circulates around until all the material is the same temperature

Three Ways Heat Travels Conduction is heat produced my molecular action. Warm molecules move around bumping into cooler molecules. This continues to happen until all the molecules are the same temperature. We see it most in how an automobile engine is cooled and how we cook our food. Radiation is heat produced through waves of energy such as light. Particles are bundles of energy that give off their heat energy upon striking a surface they cannot pass through.

Renewable, Non-Renewable, and Inexhaustible First, what is the difference between a renewable energy resource, non-renewable energy resource, and an inexhaustible energy resource? Answer: A renewable energy resource is a resource that can be replenished meaning once it is used up there will be another one that can be used. Example is trees, once we cut one down we can plant another one and keep the cycle going.

Renewable, Non-Renewable, and Inexhaustible A Non-Renewable energy resource is energy that once it is used up there is no more. Oil is an example, once the oil runs out there is no more. An Inexhaustible energy resource is one that will never run out. An example is the energy from the sun, water, and wind.

Evolution of Energy Conversions The ways humans have used energy for their survival has changed dramatically over the years. Humans used to use rocks to throw before learning they could shape the rocks into better weapons. Then using fire to heat the edges of stones and drop cold water onto them breaking away the small chips until good edges were formed. From weapons humans were able to develop crude but useful tools. With these tools they were able to grow their food and kill more animals

Evolution of Energy Conversions Then they tamed the wild animals which provided both a source of food and mechanical energy. This allowed them to more easily work the soil and make better tools. Humans then started to use the natural energy of the earth to help them. They used windmills which were attached to a vertical shaft which was attached to gears, belts, and pulleys. Later water power was used in the form of waterwheels. First there was the undershot waterwheel which allowed the water to flow underneath it to power the wheel.

Evolution of Energy Conversions Then came the overshot waterwheel which was a huge improvement over the undershot. It used the natural momentum of the water plus the extra weight of the water flowing downstream to give the wheel the extra power. It could work harder and power heavier loads. Due to the overall lack of constant power from the waterwheels there came a water turbine. It was much more efficient. Next humans began to use heat to produce motion energy. Heat engines contain the energy of heat to make it do work.

Evolution of Energy Conversions Next came the steam engine. Humans didn’t know how important this invention was because they had no real use for one yet. It was used to pump water out of deep holes for miners but later adapted to boats, tractors, and locomotives. Then came the invention of the internal combustion engine. This engine burns fuel inside the engine rather than using steam.

Modern Conversion Systems Energy can be converted from one form to another to make it more usable. Below are examples of the different ways energy gets converted: Mechanical to Electrical- Ex. Generators and alternators Electrical to Mechanical- Ex. Electric motor used to turn a fan Chemical to Electrical- Ex. Batteries

Modern Conversion Systems Electrical to Chemical- Ex. An alternator produces electricity and stores it in a battery Light to Electrical- Ex. Solar Panels collecting, storing, and changing light into electricity Molecular to Heat- Ex. Boiling water

Terms to Know Define these terms and describe how they work. They will be on a quiz next class. Undershot Waterwheel Overshot Waterwheel Internal Combustion Engine Windmill