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Fall 2005, Pflugerville ISD© Fall 2005, Pflugerville ISD, 6th Grade
6th Grade Science
Fall 2005, Pflugerville ISD
Unit 2: A World of Energy
Chapter 5:Energy and Energy Resources
Section 1: What is Energy?
Section 2: Energy Conversions
Section 3: Using Energy
Section 4: Energy Resources
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
What is Energy?
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
What is Energy?
What is energy?
What Do You Think?
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
What is Energy?
Energy is the ability to do work.
There are different kinds of energy:
– Kinetic energy
– Potential energy
Cite: http://www.nismat.org/ptcor/spondylo/gymnast.jpg
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
Kinetic energy is the energy of motion– All moving objects have kinetic energy
Kinetic energy depends on speed and mass– The faster something is moving, the more kinetic
energy it has.– The more massive a moving object is, the more
kinetic energy it has.
What is Energy?
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
Potential energy is the energy an object has because of its position or shape.
Lifting an object gives it gravitational potential energy (GPE).
Gravitational potential energy (GPE) depends on weight and height.
What is Energy?
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
Energy comes in many forms:
– Thermal energy– Chemical energy– Electrical energy– Sound energy– Light energy– Nuclear energy
What is Energy?
Cite: http://www.sirinet.net/~jgjohnso/formsofenergy.jpg
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
Thermal energy is the total energy of the particles that make up an object.
Because the particles are moving, they have kinetic energy.– At higher temperatures, the particles move faster– The faster particles move, the more kinetic energy they have and the
greater the object’s thermal energy is
Thermal energy also depends on the number of particles in a substance.
What is Energy?
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
Chemical energy is the energy stored in a substance that can be released when the substance reacts.
For example - when wood is burned, chemical energy is released.
Another example - when you eat something, your body is able to use the food’s chemical energy.
What is Energy?
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
Electrical energy is the energy of moving electrons.
When you plug in your alarm clock and turn it on, electrons in the wires move back and forth (120 times per second).
As the electrons move, energy is transferred to different parts of the clock to make it do work.
What is Energy?
Cite: http://www.aplusenergy.com/images/electrictower.jpgCite: http://cache.corbis.com/agent/11/43/86/11438695.jpg
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
What is Energy?
Sound energy is caused by an object’s vibrations.
When a guitar string vibrates, energy is transferred from the moving string to the air particles around it.
The particles transfer energy from one another and finally cause your eardrum to vibrate, and you hear the sound of the guitar.
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
Light energy is caused by the vibrations of electrically charged particles.
The vibrations that transmit light energy do not require particles to transmit energy.
Light energy, unlike sound energy, can be transmitted through a vacuum (like space).
What is Energy?
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
What is Energy?
Nuclear energy is caused by changes in the nucleus of an atom.
Nuclear energy is produced two ways:– When two or more nuclei join together (nuclear
fusion)– When the nucleus of an atom splits apart
(nuclear fission)
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
Types of Energy Review- Click here to review the types of energy.
What is Energy?
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
Make a simple drum. What do you hear? Change the way you hit the drum. What happens to the sound?
What is Energy?
Activity
See speaker notes for lab.
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
Electric current is the flow of electrons form an object that has many electrons to another object that has too few electrons. Explore circuits with a battery, wires, light bulbs, and a voltmeter.
Pre-AP Extension
See speaker notes for lab.
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
1. What is Energy?
Let’s Review
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
Energy is the ability to do work.
Answer
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
2. How are energy and work related?
Let’s Review
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
Energy is the ability to do work and work cannot be done without
energy.
Answer
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
3. What are the different forms of energy?
Let’s Review
Chapter 5 Section 1 Fall 2005, Pflugerville ISD
Thermal
Chemical
Electrical
Sound
Light
Nuclear
Answer
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Energy Conversions
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Energy Conversions
What Do You Think?
How is a moving pendulum converting potential energy to
kinetic energy?
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
An energy conversion is a change from one form of energy to another.
Any form of energy can be changed into any other form of energy.
→
Chemical EnergyKinetic Energy
Energy Conversions
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Mechanical energy is the sum of an object’s kinetic and potential energy.
Example:– When a pendulum is lifted, potential energy is
stored.– When the pendulum swings, the potential
energy is changed to kinetic energy.– The total energy is the pendulum’s mechanical
energy.
Energy Conversions
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
When you eat, the chemical energy of the food is converted by your body to other forms of energy.
Can you think of ways your body uses chemical energy?
Energy Conversions
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Take a close look at the energy conversion that occurs as a pendulum swings.
Activity
Energy Conversions
See speaker notes for lab.
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Energy Conversions
Energy conversions also occurs in plants.Plants use chlorophyll to convert light energy to chemical energy.
Cite:http://www.cneccc.edu.hk/subjects/bio/album/Chapter8/images/PHOTOSYNTHESIS0.jpg
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Machines convert electrical energy into other forms of energy.
What types of energy does a hair dryer convert electrical energy into?
Energy Conversions
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
The Law of Conservation of Energy states energy can neither be created nor destroyed.
The total amount of energy in a closed system is always the same.
Energy Conversions
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Friction is a force that opposes motion between two surfaces that are touching.
Some energy that appears to be “lost” actually becomes thermal energy due to friction.
Energy Conversions
Cite: http://www.abc.net.au/juniors/pages/2000/transport/land/img/friction.jpg
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Energy efficiency compares the amount of energy before a conversion with the amount of useful energy after the conversion.
The less energy that must be used to overcome friction, the more efficient the energy conversion.
Energy Conversions
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Energy Conversions
What do we call cars that move through the air more easily and use less energy to overcome friction?
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Energy Conversions
A perpetual motion machine is a machine that runs forever without any added energy – 100% efficient.
Because all energy conversions result in some form of energy that isn’t useful, perpetual motion is impossible.
Cite: http://www.w-uh.com/images/perpetual_wheel.gif
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
View some examples of energy conversions by clicking here.
Energy Conversion
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Design a protection system for an egg so you can drop it without it breaking thus the energy transfer will go into your protection system and not the shell.
Energy Conversions
Activity
See speaker notes for lab.
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Explore the different forms of energy associated with different object and mechanisms and how they convert energy from one form to another.
Pre-AP Extension
See speaker notes for lab.
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
1. Identify three energy transformations occurring during
the production of energy for human use.
Let’s Review
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Sample answer: A battery converts chemical energy into
electrical energy.
Answer
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
2. Describe the energy conversions that take place when you ride in a
car.
Let’s Review
Chapter 5 Section 2 Fall 2005, Pflugerville ISD
Sample answer: The car converts the chemical energy from
gasoline into thermal energy; which is then used to do work on the pistons. This gives the car
kinetic energy.
Answer
Chapter 5 Section 3 Fall 2005, Pflugerville ISD
Using Energy
Chapter 5 Section 3 Fall 2005, Pflugerville ISD
What Do You Think?
How is energy transferred when you are riding a bike?
Using Energy
Chapter 5 Section 3 Fall 2005, Pflugerville ISD
A machine is a device that can make work easier by changing the direction or size of force needed to do work.
Machines cannot transfer or change more energy than you transfer to them.
Using Energy
Chapter 5 Section 3 Fall 2005, Pflugerville ISD
When machines transfer energy, they can also convert energy.
Your alarm clock is an example: It transfers electrical energy to sound energy to help you wake up in the morning.
What are some other examples of machines causing energy conversions?
Using Energy
Chapter 5 Section 3 Fall 2005, Pflugerville ISD
Heating systems move thermal energy to cooler areas.
Air or water is used to move thermal energy from burning fuel to other areas of a house or building.
Using Energy
Chapter 5 Section 3 Fall 2005, Pflugerville ISD
Solar heating systems convert light energy from the sun into thermal energy.
Active solar heating systems have moving parts – machines that move the sun’s energy throughout a building (such as pipes, fans, and storage tanks for water to be heated).
Passive solar heating systems do not have moving parts – they use thick walls and large windows that face south.
Using Energy
Chapter 5 Section 3 Fall 2005, Pflugerville ISD
Using Energy
Cooling systems move thermal energy out of the area that is to be cooled.
To move thermal energy from a cool area (indoors) to a warm area (outdoors), a cooling system must do work.
Cite: http://img.epinions.com/images/opti/8c/48/Amana_Touch_Cooling_Series_Room_Air_Conditioner_Model_AAC081STA-resized200.jpg
Chapter 5 Section 3 Fall 2005, Pflugerville ISD
Most cooling systems use electrical energy to do the work of cooling.
A machine called a compressor does the work of compressing a refrigerant.
A refrigerant is a gas that can easily change state to become liquid.
Using Energy
Chapter 5 Section 3 Fall 2005, Pflugerville ISD
Have a guest speaker come in such as an air conditioning expert to talk to the kids about refrigerators and heating systems.
Activity
Using Energy
Chapter 5 Section 3 Fall 2005, Pflugerville ISD
1. What is the role of machines in energy transfer?
Let’s Review
Chapter 5 Section 3 Fall 2005, Pflugerville ISD
Machines can transfer energy from one object to another as
they make work easier.
Answer
Chapter 5 Section 3 Fall 2005, Pflugerville ISD
2. Compare the hot-water heating system and an active solar
heating system.
Let’s Review
Chapter 5 Section 3 Fall 2005, Pflugerville ISD
Both systems use pumps to move heated water throughout the house. The thermal energy used to heat the water comes from burning fuel in a
hot-water system and from the sun in an active solar heating system.
Answer
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
Energy Resources
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
What Do You Think?
What are some of the energy resources we use everyday?
Energy Resources
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
An energy resource is a natural resource that people can turn into other forms of energy in order to do useful work.
Nonrenewable resources cannot be replaced after they are used or can only be replaced over thousands or millions of years.
Energy Resources
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
Fossil Fuels such as coal, petroleum, and natural gas formed from the buried remains of plants and animals that lived millions of years ago.
The stored energy of these remains is released when the fossil fuels are burned.
Energy Resources
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
Coal – most coal in the U.S. is burned in power plants to generate electrical energy.Petroleum – gasoline, kerosene, wax, and other petrochemicals come from petroleum.Natural Gas – the cleanest burning fossil fuel is used in heating systems, stoves and ovens, and a few vehicles.
Energy Resources
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
1. The chemical energy of the fossil fuel is turned to thermal energy by burning.
2. Thermal energy is used to boil water and change it to steam.
3. Thermal energy is changed to mechanical energy as steam pushes against the blades of a turbine.
Energy Resources
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
Energy Resources
4. An electric generator changes mechanical energy into electrical energy.
5. The electrical energy can be sent to homes and businesses through electrical wires.
Cite: http://newsimg.bbc.co.uk/media/images/39132000/jpg/_39132217_electricity_203.jpg
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
Nuclear power plants also generate thermal energy that boils water to produce steam.
Nuclear energy is generated from radioactive elements such as uranium.
In a nuclear power plant, a special process splits the nucleus of a uranium atom in two – giving off nuclear energy.
Energy Resources
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
Renewable energy resources can be used and replaced in nature over a short period of time.
– Solar Energy– Energy from water– Wind energy– Geothermal energy– Biomass
Energy Resources
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
Solar Energy – sunlight can be changed into electrical energy by solar cells.Energy from water – the potential energy of water in a reservoir can be changed into kinetic energy as the water flows downhill through a dam. The kinetic energy of the falling water turns turbines, which change it to electrical energy by turning a generator.Wind Energy – the kinetic energy of wind can turn the blades of a windmill. A wind turbine changes the kinetic energy of the air into electrical energy by turning a generator.
Energy Resources
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
Geothermal energy – Thermal energy caused by the heating of Earth’s crust is used by pumping water underground into areas of hot rock. The water returns to the surface as steam – which can then be used to turn a generator to change mechanical energy into electrical energy.
Energy Resources
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
Energy Resources
Geothermal heating and cooling.
Cite: http://www.rlcave.com/cooling%20_animation.gif
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
Energy Resources
Biomass – plants use an store energy from the sun. Organic matter that can be burned to release energy is called biomass. Some plants can be turned into liquid fuel - for example, corn can be used to make ethanol.
Cite: http://cr.middlebury.edu/es/altenergylife/biomass!!.jpg
Cite: http://www.caribbeanedu.com/images/kewl/biomass01.gif
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
1. 100 tons of plant matter (the amount that exists in 40 acres of wheat)
2. Burning that gallon puts 20 lbs. of CO2 into the air.
3. The U.S. consumes 131 billion gallons of gas annually = 25 quadrillion lbs. of biomass = putting 26 trillion lbs. of CO2 into the air.
4. Since 1751, humans have burned the amount of fossil fuels that would have come from all the plants on Earth for 13,300 years.
Energy Resources
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
Nonrenewable resources will exhaust over time. Conservation is a way of using less energy along with the increase use of renewable resources. Explore the deletion of fossil fuel and the need to conserve and develop renewable resources.
Pre-AP Extension
See speaker notes for lab.
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
1. Describe fossil fuels and biomass from their source to their
use.
Let’s Review
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
Fossil fuels are formed from the remains of plants and animals that
lived millions of years ago, and biomass is organic matter that is obtained from things living today.
Both are burned to released chemical energy, which can be converted into
other forms of energy.
Answer
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
2. Determine whether the following energy types are renewable,
nonrenewable, or inexhaustible:–Nuclear energy
–Solar energy–Biomass
Let’s Review
Chapter 5 Section 4 Fall 2005, Pflugerville ISD
Nuclear energy is nonrenewable.
Solar energy is inexhaustible.
Biomass is renewable.
Answer
