Unit D Lesson 10: Energy Types and Transformations
Completion requirements
Unit D Lesson 10: Energy Types and Transformations
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Learning Targets |
Big Question: What Types of
Energy
Transformations Occur?
You need energy. You get energy directly and indirectly from sources like foods, fuels, and even the Sun.
You need energy. You get energy directly and indirectly from sources like foods, fuels, and even the Sun.
At the end of this inquiry, you should be able to answer the following questions:
- What are four forms of energy?
- What is the function of a thermocouple?
Pages 318 and 323 in your textbook will help you answer these questions.
Introduction
Energy Changes From One Form To Another
Energy changes occur all around us everyday. What energy changes occur for the runner in Figure 1? How does the runner get the energy to move?
Consider some of the energy changes that are occurring when you wake up in the morning, get dressed, and have breakfast. Energy changes will continue to occur all around you throughout the rest of the day. You will learn more about these changes throughout this lesson.
The alarm clock rings and you get out of bed – you are using energy. When you put bread in the toaster, you are using energy. When you get on the bus to go to school, you are using energy. What is the source of all this energy?
Energy is the ability to do work.
The alarm clock, toaster, and bus all need energy to work. Energy must come from somewhere. Energy has many forms: chemical, mechanical, thermal, electrical, and light are just a few.
According to the First Law of Conservation of Energy, energy can neither be created nor destroyed but only changes from one form to another.
Energy changes occur all around us everyday. What energy changes occur for the runner in Figure 1? How does the runner get the energy to move?
Consider some of the energy changes that are occurring when you wake up in the morning, get dressed, and have breakfast. Energy changes will continue to occur all around you throughout the rest of the day. You will learn more about these changes throughout this lesson.
The alarm clock rings and you get out of bed – you are using energy. When you put bread in the toaster, you are using energy. When you get on the bus to go to school, you are using energy. What is the source of all this energy?
Energy is the ability to do work.
The alarm clock, toaster, and bus all need energy to work. Energy must come from somewhere. Energy has many forms: chemical, mechanical, thermal, electrical, and light are just a few.
According to the First Law of Conservation of Energy, energy can neither be created nor destroyed but only changes from one form to another.
Figure 1 – You can't run without energy.
Types and Forms of Energy
There are several different types and forms of energy. They are all very important, but we will take a detailed look at specific types – please read the following list carefully.
Chemical Energy
Chemicals have the ability to do work. When we mix chemicals that are suitable for a chemical reaction, other types of energy can be produced by the rearrangement of bonds. For example, if the chemical reaction is explosive, some of the chemical energy is being transformed to heat and light. Recall the chemical reaction in a battery from Section 1.4. When the chemicals combine in a battery, the chemical energy is transformed into electrical energy.
Another example of the use of chemical energy is in food digestion. Foods, which contain chemical energy, travel through our digestive system where they undergo many chemical reactions. The food is broken down into molecules that travel to our cells, which are further broken down to provide the energy that helps us move (mechanical energy) and keep us warm (thermal energy).
Chemicals have the ability to do work. When we mix chemicals that are suitable for a chemical reaction, other types of energy can be produced by the rearrangement of bonds. For example, if the chemical reaction is explosive, some of the chemical energy is being transformed to heat and light. Recall the chemical reaction in a battery from Section 1.4. When the chemicals combine in a battery, the chemical energy is transformed into electrical energy.
Another example of the use of chemical energy is in food digestion. Foods, which contain chemical energy, travel through our digestive system where they undergo many chemical reactions. The food is broken down into molecules that travel to our cells, which are further broken down to provide the energy that helps us move (mechanical energy) and keep us warm (thermal energy).
Mechanical Energy
Mechanical energy is due to object’s potential to move and/or the object’s actual movement. Mechanical energy is the total potential and kinetic energy an object possesses. Potential energy is stored energy due to gravity, such as standing at the top of hill. This potential energy is converted into kinetic energy (the energy of motion) when something moves down a hill. For example, in downhill skiing, the skier has maximum potential energy at the top of the hill. When the skier starts moving, his or her potential energy changes into kinetic energy.
Mechanical energy can be transformed into other forms of energy. For example, a windmill uses wind energy to produce a movement in the windmill. Both the motion of the wind and the motion of the windmill are mechanical energy – the generator of the windmill in turn changes the mechanical energy into electric energy.
Mechanical energy is due to object’s potential to move and/or the object’s actual movement. Mechanical energy is the total potential and kinetic energy an object possesses. Potential energy is stored energy due to gravity, such as standing at the top of hill. This potential energy is converted into kinetic energy (the energy of motion) when something moves down a hill. For example, in downhill skiing, the skier has maximum potential energy at the top of the hill. When the skier starts moving, his or her potential energy changes into kinetic energy.
Mechanical energy can be transformed into other forms of energy. For example, a windmill uses wind energy to produce a movement in the windmill. Both the motion of the wind and the motion of the windmill are mechanical energy – the generator of the windmill in turn changes the mechanical energy into electric energy.
Figure 2 – A skier moving downhill has mechanical energy.
Electrical Energy
Electrical energy is the energy created by the movement of charged particles. Most often, the charged particles are electrons. We use cell phones, computers, and many other devices in our home thanks to electrical energy.
Thanks to devices such as heating elements, light bulbs, and motors, electrical energy can be transformed into various types of energy such as heat, light, and mechanical. For example, in a toaster, electrical energy is transformed into heat and light energy. In a fluorescent light bulb, electricity excites a gas, which produces both light and heat energy.
Electrical energy is the energy created by the movement of charged particles. Most often, the charged particles are electrons. We use cell phones, computers, and many other devices in our home thanks to electrical energy.
Thanks to devices such as heating elements, light bulbs, and motors, electrical energy can be transformed into various types of energy such as heat, light, and mechanical. For example, in a toaster, electrical energy is transformed into heat and light energy. In a fluorescent light bulb, electricity excites a gas, which produces both light and heat energy.
Figure 3 – Incandescent bulbs are being used less and less, because they produce a lot of waste heat while converting electrical energy into light energy.
Thermal Energy
Thermal energy refers to the total kinetic energy of particles in a substance. The amount of thermal energy is directly proportional to the speed the particles are moving. The faster the particles move, the more thermal energy. Thermal energy can be transferred by direct touch, for example, if your cold hand touches a warm loaf of bread, thermal energy in the bread will be transferred to your hand. If particles of a substance move fast enough, it is possible for them to emit thermal radiation, which can travel from place to place without direct touch.
The most familiar sources of thermal energy are heating devices. Most Canadians are familiar with fireplaces, keeping us warm during our long winters. The fireplace is an excellent example of a heating device. It's also an excellent example of different types of energy conversions, since they come in wood burning, gas, alcohol, and electric versions.
Thermal energy refers to the total kinetic energy of particles in a substance. The amount of thermal energy is directly proportional to the speed the particles are moving. The faster the particles move, the more thermal energy. Thermal energy can be transferred by direct touch, for example, if your cold hand touches a warm loaf of bread, thermal energy in the bread will be transferred to your hand. If particles of a substance move fast enough, it is possible for them to emit thermal radiation, which can travel from place to place without direct touch.
The most familiar sources of thermal energy are heating devices. Most Canadians are familiar with fireplaces, keeping us warm during our long winters. The fireplace is an excellent example of a heating device. It's also an excellent example of different types of energy conversions, since they come in wood burning, gas, alcohol, and electric versions.
Figure 4 – A fireplace is a cozy source of thermal energy.
Light/Solar Energy
Light from the sun is the main source of energy for Earth. It's common to hear the light energy from the sun referred to as solar energy. In any case, light is actually a form of electromagnetic energy (EMR). There are many forms of EMR, many of which are invisible, but the one we know the best is the visible , which is light. Light carries with it energy, which plants use to create food energy, and humans use in a variety of technological applications.
Light from the sun is the main source of energy for Earth. It's common to hear the light energy from the sun referred to as solar energy. In any case, light is actually a form of electromagnetic energy (EMR). There are many forms of EMR, many of which are invisible, but the one we know the best is the visible , which is light. Light carries with it energy, which plants use to create food energy, and humans use in a variety of technological applications.
Figure 5 – Light from the sun makes life on Earth possible.
Connections
Connections – Energy Conversion Technologies
>> Thermocouples
An important example of where thermal energy is transformed into electrical energy is a thermocouple.
Thermocouples are made of two metals connected at one end; these metals heat at different rates. The difference in the rates produces an electric current. The greater the heat difference in the metals means the greater the current and therefore, the greater the temperature.
Thermocouples are effective in areas that experience high temperatures in locations that are difficult to reach such as household furnaces, dryers, and hot-water heaters as well as smokestacks in buildings, and towers in refineries. Thermocouples are also excellent devices for measuring temperature in very hot situations, where typical thermometers would be destroyed.
>> Thermocouples
An important example of where thermal energy is transformed into electrical energy is a thermocouple.
Thermocouples are made of two metals connected at one end; these metals heat at different rates. The difference in the rates produces an electric current. The greater the heat difference in the metals means the greater the current and therefore, the greater the temperature.
Thermocouples are effective in areas that experience high temperatures in locations that are difficult to reach such as household furnaces, dryers, and hot-water heaters as well as smokestacks in buildings, and towers in refineries. Thermocouples are also excellent devices for measuring temperature in very hot situations, where typical thermometers would be destroyed.
Figure 6 – Thermocouples can be very important to other technologies. Here, scientists at the Idaho National Laboratory design highly accurate thermocouples for inside nuclear reactors. Courtesy INL.
>> Piezoelectrics
Did you know that crystals, ceramic, bones, and DNA can produce electricity when squeezed? This effect is called piezoelectricity. The piezoelectric effect was discovered in the late 1800s by scientists Jacques and Marie Curie.
Everyday uses of the piezoelectric effect are seen in barbecue lighters, fish finders, and digital watches. When you push the barbecue lighter, a little hammer hits a quartz crystal and makes a small voltage, but it is big enough to ignite the gas to light the barbecue. The energy resulting from the movement and pressure changes into electrical energy.
The piezoelectric effect can also work in reverse. Applying electricity to peizoelectric crystals will make them move. They move very rapidly and precisely, which makes them very useful in many new advanced technologies.
Did you know that crystals, ceramic, bones, and DNA can produce electricity when squeezed? This effect is called piezoelectricity. The piezoelectric effect was discovered in the late 1800s by scientists Jacques and Marie Curie.
Everyday uses of the piezoelectric effect are seen in barbecue lighters, fish finders, and digital watches. When you push the barbecue lighter, a little hammer hits a quartz crystal and makes a small voltage, but it is big enough to ignite the gas to light the barbecue. The energy resulting from the movement and pressure changes into electrical energy.
The piezoelectric effect can also work in reverse. Applying electricity to peizoelectric crystals will make them move. They move very rapidly and precisely, which makes them very useful in many new advanced technologies.
Figure 7 – The most advanced engines in the world use peizoelectric direct fuel injectors. These injectors allow for very precise control over how the fuel enters the engine. Courtesy Peter Stevens.
>> Photovoltaics
Commonly called solar panels, photovoltaic cells transform the sun’s energy into electrical energy. Thanks to recent advances in technology, solar panels are an inexpensive way to gain electricity.
Photovoltaic cells are used to power emergency phones on the roadsides and some streetlights. During the day, they trap the sun’s energy, and at night, the light is converted to electricity to power the device.
You might know of several applications of these cells, including the large panels on roofs or on special stands. You might have seen solar farms, which are fields covered with stands of photovoltaic cells.
Smaller versions might charge your recreation vehicle batteries or operate a farmer’s electric fencer or cattle-watering pump. In fact, you might have a small version on your watch or your pocket calculator.
Commonly called solar panels, photovoltaic cells transform the sun’s energy into electrical energy. Thanks to recent advances in technology, solar panels are an inexpensive way to gain electricity.
Photovoltaic cells are used to power emergency phones on the roadsides and some streetlights. During the day, they trap the sun’s energy, and at night, the light is converted to electricity to power the device.
You might know of several applications of these cells, including the large panels on roofs or on special stands. You might have seen solar farms, which are fields covered with stands of photovoltaic cells.
Smaller versions might charge your recreation vehicle batteries or operate a farmer’s electric fencer or cattle-watering pump. In fact, you might have a small version on your watch or your pocket calculator.
Figure 8 – Solar panels are becoming a popular upgrade to many homes.
Watch
Watch the following videos for more information on energy sources, energy conversions, and energy technologies.
Did you know the Cassini Probe that explored the rings of Saturn used a thermocouple to generate the electricity needed to run the radio? To learn more about thermocouples, watch "Thermocouple".
Imagine generating electricity while just moving around! There has been a lot of research into harnessing the energy of human movement through the use of piezoelectrics. Watch the following video, "How does the Piezoelectric Energy Harvesting Generate Power?"
For additional information on the application of photovoltaic cells in Canada, watch "How do Solar Panels Produce Electricity".
Try It!
Practice Worksheet: Energy Skate Park Basics
- DOWNLOAD this practice worksheet (S9_UD_S3_L10a_skate_park). If you prefer to use a Google Drive or PDF version of the worksheet, click here.
- Click here to visit the simulation website. Follow
the instructions on the worksheet and answer the questions.
- When you are satisfied with your responses you can check your work by clicking on the "SUGGESTED ANSWERS" button below.
Wait! Don't view the suggested answers first. This practice work is not for marks, it is meant to help you check your understanding. Check the answers AFTER doing the questions! Keep the practice worksheet for study purposes. If you don't understand something, contact your teacher!
1. The total energy stays the same the entire time. The total energy is also known as the mechanical energy of the system.
Mechanical energy = Potential energy + Kinetic energy.
2. The potential energy is changed into kinetic energy as the skater travels from the top of the ramp to the bottom. The total energy always remains constant. This is the mechanical energy.
Mechanical energy = Kinetic energy + Potential energy.
Mechanical energy = Potential energy + Kinetic energy.
2. The potential energy is changed into kinetic energy as the skater travels from the top of the ramp to the bottom. The total energy always remains constant. This is the mechanical energy.
Mechanical energy = Kinetic energy + Potential energy.
Try It!
Practice Worksheet: Energy Convserions
- DOWNLOAD this practice worksheet (S9_UD_S3_L10b_energy_conversions). If you prefer to use a Google Drive or PDF version of the worksheet, click here.
- Follow the instructions on the worksheet and answer the questions.
- When you are satisfied with your responses you can check your work by clicking on the "SUGGESTED ANSWERS" button below.
Wait! Don't view the suggested answers first. This practice work is not for marks, it is meant to help you check your understanding. Check the answers AFTER doing the questions! Keep the practice worksheet for study purposes. If you don't understand something, contact your teacher!
Remember the following are just suggestions, you devices might be different. That's OK! If you want feedback, share your worksheet with your teacher.
