Transcript intro to energy unit 1

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?
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