Unit C Lesson C8 Thermal Energy: Natural Sources
Completion requirements
Lesson C8: Thermal Energy: Natural Sources
Video Lesson
Where does thermal energy come from? Watch this video to learn about some natural sources of thermal energy.
Lesson C8: Thermal Energy: Natural Sources
Figure C.3.8.1– People use fire to heat and cook food.
Figure C.3.8.2– Uncontrolled fires are very destructive.
What is Fire?
Fire has been a useful heat source for humans. People use fire for heating homes, cooking food, and producing light.
Fire is what we see during a type of chemical reaction called combustion. Combustion is a reaction that produces heat, light, carbon dioxide, and water.
Combustion requires a fuel, oxygen gas, and a hot spark. Without all three components, a fire will not start.
Fire has been a useful heat source for humans. People use fire for heating homes, cooking food, and producing light.
Fire is what we see during a type of chemical reaction called combustion. Combustion is a reaction that produces heat, light, carbon dioxide, and water.
Combustion requires a fuel, oxygen gas, and a hot spark. Without all three components, a fire will not start.
Reading and Materials for This Lesson:
Science in Action 7
Materials:
Science in Action 7
Reading: Pages 222–224
Materials:
sheet of paper towel, water, wood cutting board, masking tape, 2 chocolate candies in wrappers, hair dryer, ruler, timer
Watch More
Fire
Watch this cartoon to learn more about the chemical reaction that results in fire.
Watch this cartoon to learn more about the chemical reaction that results in fire.
Connections
Connections: Health
>> Calories
All packaged food must contain nutrition labels. The number of calories in a food serving is listed at the top of the nutrition label. The number of calories is a measurement of chemical energy in food.
Calories are not a bad thing despite what dieters say! All food has calories, or chemical energy. We need chemical energy to stay alive. Our bodies uses some of the calories in food to move our muscles and to keep our brains thinking. Our bodies change some of the calories in food to thermal energy. Thermal energy keeps our bodies at constant warm temperatures.
Reading nutrition labels can help you plan healthy meals. To be healthy, you need to eat the appropriate amounts of calories for your age and height. You should not eat excessive amounts of calories nor should you eat too few calories.
You don’t need to count calories to eat healthy meals! Eating the right number of servings of a variety of healthy foods is important. You can learn how to make healthy food choices through the Canada Food Guide appropriate for your age.
>> Calories
All packaged food must contain nutrition labels. The number of calories in a food serving is listed at the top of the nutrition label. The number of calories is a measurement of chemical energy in food.
Calories are not a bad thing despite what dieters say! All food has calories, or chemical energy. We need chemical energy to stay alive. Our bodies uses some of the calories in food to move our muscles and to keep our brains thinking. Our bodies change some of the calories in food to thermal energy. Thermal energy keeps our bodies at constant warm temperatures.
Reading nutrition labels can help you plan healthy meals. To be healthy, you need to eat the appropriate amounts of calories for your age and height. You should not eat excessive amounts of calories nor should you eat too few calories.
You don’t need to count calories to eat healthy meals! Eating the right number of servings of a variety of healthy foods is important. You can learn how to make healthy food choices through the Canada Food Guide appropriate for your age.
Figure C.3.8.3– Packaged food is marked with nutrition labels.
Figure C.3.8.4– Calories are measurements of the amount of chemical energy in a food serving.
Watch More
Calories in Food
This video shows an experiment testing how much thermal energy is produced by burning various types of food.
This video shows an experiment testing how much thermal energy is produced by burning various types of food.
Warm-Blooded and Cold-Blooded Animals
Warm-blooded animals, such as mammals and birds, keep constant warm body temperatures. Animals with constant body temperatures are always alert and able to move quickly away from predators.
To move quickly, animals need warm muscles. To maintain warm muscles, warm-blooded animals eat frequently. The chemical energy in food changes into thermal energy in the body, which keeps muscles warm and ready to move.
Cold-blooded animals, such as reptiles and most fish, do not keep constant body temperatures. The body temperature of cold-blooded animals depends on the temperature of the surrounding environment. Cold-blooded animals do not need to eat frequently because they do not need to keep their muscles constantly warm. This means that cold-blooded animals move slower in cold environments.
Warm-blooded animals, such as mammals and birds, keep constant warm body temperatures. Animals with constant body temperatures are always alert and able to move quickly away from predators.
To move quickly, animals need warm muscles. To maintain warm muscles, warm-blooded animals eat frequently. The chemical energy in food changes into thermal energy in the body, which keeps muscles warm and ready to move.
Cold-blooded animals, such as reptiles and most fish, do not keep constant body temperatures. The body temperature of cold-blooded animals depends on the temperature of the surrounding environment. Cold-blooded animals do not need to eat frequently because they do not need to keep their muscles constantly warm. This means that cold-blooded animals move slower in cold environments.
Figure C.3.8.5– Warm-blooded animals are always able to move quickly.
Figure C.3.8.6– Because they are mammals, whales are warm-blooded animals.
Figure C.3.8.7– Lizards are cold-blooded animals.
Watch More
Warm-Blooded vs. Cold-Blooded: What’s The Difference?
Watch this video to learn more about how heat affects warm-blooded and cold-blooded animals.
Watch this video to learn more about how heat affects warm-blooded and cold-blooded animals.
Human Body Temperature
The normal average human body temperature is 37°C. A person’s regular body temperature rises or falls slightly by less than 1°C during the day.
Fevers occur when a person’s body temperature rises above 38°C. When disease-causing viruses or bacteria enter the body, the immune system heats the body to kill these invaders. Often, fevers are accompanied by perspiring. When a person’s body temperature is higher than normal, the skin produces perspiration to cool the body.
Slight fevers help the immune system fight disease, but high fevers are dangerous. A sick person should see a doctor if a fever rises to more than 40°C or if a fever lasts longer than two or three days.
Hypothermia occurs when a person’s body temperature drops below 35°C. Hypothermia involves the body losing heat faster than it can produce heat from chemical energy. A low body temperature affects the brain. A hypothermic person can become confused and unconscious. People get hypothermia from being outside in extremely cold conditions without sufficient insulating clothing.
The normal average human body temperature is 37°C. A person’s regular body temperature rises or falls slightly by less than 1°C during the day.
Fevers occur when a person’s body temperature rises above 38°C. When disease-causing viruses or bacteria enter the body, the immune system heats the body to kill these invaders. Often, fevers are accompanied by perspiring. When a person’s body temperature is higher than normal, the skin produces perspiration to cool the body.
Slight fevers help the immune system fight disease, but high fevers are dangerous. A sick person should see a doctor if a fever rises to more than 40°C or if a fever lasts longer than two or three days.
Hypothermia occurs when a person’s body temperature drops below 35°C. Hypothermia involves the body losing heat faster than it can produce heat from chemical energy. A low body temperature affects the brain. A hypothermic person can become confused and unconscious. People get hypothermia from being outside in extremely cold conditions without sufficient insulating clothing.
Figure C.3.8.8– Thermometers measure body temperature.
Figure C.3.8.9– A normal human body temperature is 37˚C. Body temperatures higher than 37˚C are fevers.
Watch More
Human Body Temperature
Watch this video to learn more about why various people have slightly different body temperatures.
Watch this video to learn more about why various people have slightly different body temperatures.
This video talks about body sweat (perspiration) and how it works to keep you cool.
Try It!
Cool Body Sweat
Try this simple experiment to see how sweating keeps your skin cooler.
Materials:
Try this simple experiment to see how sweating keeps your skin cooler.
Materials:
- sheet of paper towel
- water
- wood cutting board
- masking tape
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2 chocolate candies in wrappers
- hair dryer
- ruler
-
timer
Instructions:
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Cut the sheet of paper towel in half.
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Sprinkle some water on one piece of paper towel. It should be damp but not sopping wet.
- Keep both candies in their wrappers. Wrap one candy tightly with the dry paper towel, and wrap the other candy tightly with the wet paper towel. Use tape to fasten the ends of the paper towel.
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Use tape to secure both candies side by side but not touching on a wood cutting board.
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Hold the hair dryer 30 cm above the candies.
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Start the timer and blow hot air on the candies for 3 minutes.
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Turn off the hair dryer after 3 minutes.
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Observe the paper towels. What do you notice?
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Open the candy wrapper and observe the candy inside. What do you notice? (...and, yes, you can eat them after you write your answers to the questions!)
Questions:
Think about the following questions very carefully. Then, type or write your answers. After you have your answers, click the questions for feedback.
Think about the following questions very carefully. Then, type or write your answers. After you have your answers, click the questions for feedback.
Both candies were surrounded by thermal energy. However, the water in the wet paper towel absorbed thermal energy from the surroundings. This caused the water to evaporate, which prevented the candy from absorbing extra thermal energy. However, thermal
energy from the air was transferred directly to the candy wrapped in dry paper towel caused it to melt faster.
When your body temperature increases on a hot day, your body perspires, producing sweat. Thermal energy from your body is absorbed by the sweat, causing the sweat to evaporate. The transfer of thermal energy from your body into the sweat decreases the
temperature of your body.
Home Heating
Home heating is very important in Canada where we have long, cold winters. Canadians heat their homes with various natural sources of thermal energy. Most Albertans use the chemical energy in natural gas to heat their homes. Many Atlantic Canadians heat their homes with oil that is stored in outdoor tanks. Some rural Canadians heat their homes with wood fires.
To learn more about home heating systems,
click here to Explore with Elsie.
Make sure you have understood everything in this lesson. Use the Self-Check below, and the Self-Check & Lesson Review Tips to
guide your learning.
Unit C Lesson 8 Self-Check
Instructions
Complete the following 6 steps.
Don't skip steps – if you do them in order, you will confirm your
understanding of this lesson and create a study bank for the future.
- DOWNLOAD the self-check quiz by clicking here.
- ANSWER all the questions on the downloaded quiz in the spaces provided. Think carefully before typing your answers. Review this lesson if you need to. Save your quiz when you are done.
- COMPARE your answers with the suggested "Self-Check Quiz Answers" below. WAIT! You didn't skip step 2, did you? It's very important to carefully write out your own answers before checking the suggested answers.
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REVISE your quiz answers if you need to. If you answered all the questions correctly, you can skip this step. Revise means to change, fix, and add extra notes if you need to. This quiz is NOT FOR MARKS, so it is perfectly OK to correct
any mistakes you made. This will make your self-check quiz an excellent study tool you can use later.
- SAVE your quiz to a folder on your computer, or to your Private Files. That way you will know where it is for later studying.
- CHECK with your teacher if you need to. If after completing all these steps you are still not sure about the questions or your answers, you should ask for more feedback from your teacher. To do this, post in the Course Questions Forum, or send your teacher an email. In either case, attach your completed quiz and ask; "Can you look at this quiz and give me some feedback please?" They will be happy to help you!
Self-Check Time!
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Self-Check Quiz Answers
Click each of the suggested answers below, and carefully compare your answers to the suggested answers.
If you have not done the quiz yet – STOP – and go back to step 1 above. Do not look at the answers without first trying the questions.
Fire needs oxygen to keep burning. After a few minutes, all the oxygen under the jar is used up, which extinguishes the fire.
The natural source of energy in fuels is chemical energy. The chemical bonds in fuels contain energy that is released as heat when fuels are burned.
The natural source of energy heating the wood is mechanical force. The movement of the saw against the wood causes friction, which produces heat.
Warm-blooded animals maintain constant body temperatures by eating frequently. Chemical bonds in food contain energy that is changed to heat in a warm-blooded animal’s body. When warm-blooded animals eat constantly, their bodies are changing
chemical energy to thermal energy constantly.
Some places in the world are much more geothermally active than other parts of the world are. For example, Iceland has many active volcanoes and hot springs, so it has sources of geothermal energy that are easily accessible . Canada has fewer
geothermally active areas, so we cannot depend on geothermal energy for all our heating needs. We need more hot springs!