Download SCI24U2L1 - Forms of Energy

SCI24U2L1 - Forms of Energy
Unit 2: Understanding Common Energy Conversion Systems
Lesson 1 - Forms of Energy
Approximate Lesson Length: 3 hours
Subject Line for Email: SCI24U2L1
Lesson Objectives:
Upon completion of this lesson the student will be able to:
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learn about energy, kinetic energy, and potential energy;
review the relationship between kinetic and potential energy;
learn about many types of energy;
observe how the Sun's energy is collected
explain how a hybrid car works.
define input energy and output energy;
identify and work with the three components of an energy conversion;
evaluate when thermal energy is considered waste energy;
understand the Law of Conservation of Energy
examine everyday examples that illustrate the Law of Conservation of Energy
Lesson Links
Please click on any of the links below to take you to the specific section of the lesson.
What is Energy?
Energy Conversions
Law of Conservation of Energy
Lesson Review
Assignment
Introduction
Welcome to unit 2! In this unit, you will study energy transformations and conservation. You will investigate machines that generate electricity from other forms of
energy. You will also study the importance of balancing the amount of food energy you take in against your energy requirements throughout your life. Let's begin!
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Lesson
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SCI24U2L1 - Forms of Energy
What is Energy?
Energy is the ability to do work. Potential energy is stored energy that can be converted into other forms. A ball sitting on the top of a ramp has potential energy.
Kinetic energy is energy due to motion. When the ball rolls down the hill, some of the potential energy is converted to kinetic energy. At any point along the way, it
is part potential energy and part kinetic energy. But everywhere in this system, the total amount of energy is the same.
The potential energy in the food we eat is converted into other forms of energy. For example, a muffin has potential (chemical) energy.
When we eat it, our digestive system and cells convert it to other forms of energy. When we use this energy to walk or run, we have
changed potential (chemical) energy to kinetic energy.
Solar energy, or energy from the sun, provides us with food, as well as the energy we need for transportation, heat, and light. Without solar
energy, life on the Earth would not exist.
Green plants use solar energy in the process of photosynthesis to produce glucose which is their food source. Animals then eat the plants or other animals that
have eaten the plants to get their energy. Humans are not any different.
Another source of energy can include wind energy that can be captured in the form of kinetic energy in a windmill.
Geothermal energy results from volcanic activity within the Earth. You may have enjoyed this source of energy if you have been to the hot
springs in Banff or Radium.
Please refer now to pages 84 and 85 in your text and look at figure 5.4. Can you identify the forms and sources of energy in the picture?
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Energy Conversions
Each day, we rely on energy being changed from one form to another. For example, a car uses chemical energy in gasoline, and changes it to mechanical kinetic
energy of moving pistons. A digital watch uses chemical power from batteries to produce electricity. This electricity runs the watch. Wind-up watches and clocks
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SCI24U2L1 - Forms of Energy
use the potential energy in a spring to produce the mechanical kinetic energy of moving hands. If you turned on a light today, you converted electrical energy into
light energy. Can you think of any other energy conversions that you use regularly?
Internet Link(s)
http://science.howstuffworks.com/roller-coaster.htm
Learn how kinetic and potential energies change as you ride a roller coaster. Play the
simulation on "How a Roller Coaster Works" under the title "Converting Energy".
Energy conversion systems require input energy, a converter, and an output form of energy. Please refer to page 86 of your text to see some examples of
energy conversion systems.
Here are some examples:
Click here to identify the input, converter and output energy in a screwdriver
No energy conversion system is 100 percent efficient. Each time there is an energy conversion, some energy is transformed into thermal energy. In many cases,
this thermal energy is said to be "wasted". What this means is simply that some of the energy resulting from an energy conversion cannot be converted into forms
of energy we use directly. Living things use this "wasted" energy in the form of thermal energy to keep their bodies warm and therefore keep themselves alive. You
use chemical energy from food which is converted to kinetic energy for the muscles to move and thermal energy to keep you warm.
A running car converts the potential energy in the gasoline into other energies such as kinetic energy, sound energy and heat energy. If the engine converted all of
the potential energy into kinetic energy, we'd spend much less money on gasoline for our cars.
Muscular contraction in a human is an example of an energy conversion system. The input energy is the chemical energy stored in glucose. The converter is the
mitochondria in the muscle cells. The output energy is the chemical energy (ATP) that muscle cells use to contract. The chemical energy in ATP is used to do work
(ie. contract muscles). When skeletal muscles contract and relax, they move bones. (See page 86 in your text).
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Law of Conservation of Energy
In an energy conversion system, the input energy always equals the output energy. This balance is expressed in the Law of Conservation of Energy.
input energy = output energy OR input energy = useful output energy + waste output energy
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SCI24U2L1 - Forms of Energy
Sometimes energy conversion systems result in possible side effects. For example, when coal is burned, sulfur is released into the air. This sulfur is responsible for
the sulfuric or sulfurous acids that form when sulfur compounds combine with water. We need to be aware of the detrimental effects that may result from energy
conversion systems and try to minimize them.
Several car companies have developed a hybrid vehicle which uses both gasoline and electricity for its energy source. You will examine this topic further in your
assignment.
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Lesson Review
Let's review some concepts...
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Energy is the ability to do work and that it is constantly converted from one form to another.
Organisms require energy for functions such as movement.
Energy conversion systems include input energy, a converter, and output energy.
Energy can be neither created nor destroyed. Energy can, however, be converted from one form to another. For example, during cellular respiration, the
potential chemical energy in glucose is converted to a form of chemical energy that can be used for muscle contraction.
Kinetic energy is the energy of motion. Chemical energy is transformed into kinetic energy when muscle cells contract.
In this lesson we completed the following activities:
Section 1 - What is Energy?
Section 2 - Energy Conversions
Section 3 - Law of Conservation of Energy
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Conclusion
Sources of energy that we use include solar, geothermal, wind, and chemical processes. Forms of energy include light, sound, electric, thermal, kinetic, and
potential.
In your next lesson you will learn more about electrical energy and generators.
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SCI24U2L1 - Forms of Energy
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Assignment
Please read pages 78-85 in the text and answer the following questions in a Word document. Attach your completed assignment to the dropbox.
Part A: Page 85, Check Your Understanding questions 1-3.
Part B: Print the document "Energy Conversions in a Muscle Cell" and use the visuals and the text to help you interpret the way that energy is transferred from the
cellular level to the tissue level to the limbs in order to produce movement.
Word Document
Energy Conversions in a Muscle Cell
Submit your answers on the worksheet to step 1 and 2.
Part C: You are a mechanic/engineer for a large car company and have been working on the design of a new hybrid car. You are going to make a presentation to
the executive at your company explaining how the new hybrid car will work that you have been helping to design. You may use the web site below, but please also
do some research of your own. Make sure that you outline the following:
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How does a hybrid car work?
How does the electric generator work?
Why is this type of car more environmentally friendly?
Why would this car use less gas?
Internet Link(s)
http://www.howstuffworks.com/hybrid-car.htm
How hybrid cars work.
Your presentation can be in the form of a written report or a power point presentation.
Part D: Pg 90 - Energy Conversions Are Hard to Escape - Complete "What to Do" questions 1-3 and "Analyze" questions 1 and 2.
Part E: Click on the Fear of Physics-Roller Coaster web site below and follow the instructions that I have outlined below. Answer the "What did you Discover?"
questions 1-7 (listed below).
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SCI24U2L1 - Forms of Energy
1. Go to the Fear of Physics-Roller Coaster web site.
2. Select the track style that you would like to use (Track 1, Track 2, or Track 3).
3. Select the starting height of the car on your roller coaster.
4. Click “Go” and test your roller coaster.
5. Select a lower starting height for the car on the roller coaster and test it again.
6. Answer the questions that follow.
Internet Link(s)
http://www.fearofphysics.com/Roller/roller.html
Type links and description of info at each site.
What Did You Discover? (Answer these questions)
1. What determines the potential energy of a roller coaster?
2. Which has more potential energy a high roller coaster or one built closer to the ground?
3. What happens if you try to start the roller coaster when it is too close to the ground?
4. What is kinetic energy?
5. What is the relationship between the speed of a roller coaster and its kinetic energy?
6. Describe what happens to the potential and kinetic energy as a roller coaster car rolls downhill.
7. Describe what happens to the potential and kinetic energy as the car goes uphill.
Part F: Pages 96 - 97, Review. Answer questions 2-5, 8, 11.
Total Marks = 38.
Please make sure you have handed in the following:
Attach your word document containing your answers to parts A-E to your teacher using the dropbox.
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© Rocky View Virtual School - Revised August 30, 2006
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