Presentation on theme: "Big Idea 11: Energy and Energy Transformation Big Idea 6: Earth in Space Topic 8: Heat."— Presentation transcript:
Big Idea 11: Energy and Energy Transformation Big Idea 6: Earth in Space Topic 8: Heat
Benchmarks SC.3.E.6.1 Demonstrate that radiant energy from the Sun can heat objects and when the Sun is not present, heat may be lost. SC.3.P.11.1 Investigate, observe, and explain that things that give off light often also give off heat. SC.3.P.11.2 Investigate, observe, and explain that heat is produced when one object rubs against another, such as rubbing one’s hands together. Identify common materials that conduct heat well or poorly. SC.3.N.1.1 Raise questions about the natural world, investigate them individually and in teams through free exploration and systematic investigations, and generate appropriate explanations based on those explorations. SC.3.N.1.6 Infer based on observation. SC.3.N.3.2 Recognize that scientists use models to help understand and explain how things work.
What do fire, sunlight and the rubbing of hands have in common? They all produce heat energy. Chemical energy changes into heat energy when wood burns. Light energy from the sun changes into heat energy when it hits Earth. Energy of motion changes into heat energy when hands are rubbed together.
What is Heat Energy?Heat Heat energy is the energy of moving particles in any kind of matter. What happens in Heat Energy?Heat When any form of matter gets warmer, the moving energy of its atoms increases. The object’s particles move faster, so its heat energy increases. A change in heat energy can lead to a change in phase or state of matter: - Ice melts from a solid to a liquid. - Liquid water changes to water vapor.
How is it measured?measured Temperature is a measure of heat energy. A thermometer is the tool used to measure temperature.thermometer How does a thermometer work?thermometer Let’s practice reading a thermometer ◦ F = degrees Fahrenheit ◦ C = degrees Celsius
Look around the room: What are some sources of light and heat? Group 1 Things that give off light Light Sources Sunlight through the windows Ceiling lights Computer screens LCD projector Flashlight Group 2: Things that give off heat Heat Sources Sunlight Lamps Stove burners Candle flame Hot water Toaster oven Objects rubbing together How many light and heat sources are the same?
What are some examples of objects rubbing against each other and producing heat? Draw and/or write some examples in your notebook
How does sunlight affect the temperature of water? Hypothesis: If a cup of water is placed in the sun and a second cup of water is placed in the shade each for 30 minutes, the cup of water in the sun will have a (higher, lower or the same) temperature. Materials per group: 2 plastic clear cups water marker 2 thermometers measuring cup First let’s practice reading a thermometer
Procedures 1.Label 1 plastic clear cup Sunlight. Label the other plastic clear cup No Sunlight. 2.Use a measuring cup to measure ½ cup of water. 3. Pour the ½ cup of water into the cup labeled Sunlight. 4.Repeat steps 2 and 3 for the cup labeled No Sunlight. 5. Draw a data table in your science notebook. Difference
Procedures continued 6. Place a thermometer in each cup. Wait two minutes. Measure and record the beginning temperature of each cup of water on a data table in your notebook. 7. Place the Sunlight cup in the sun. Place the No Sunlight cup in the shade. 8.Wait 30 minutes. Repeat step 5. to measure and record the ending temperature for both cups. 9.Find the difference between the beginning temperature and the ending of both and record on the data chart. Compare their temperatures.
Explain the Data: 1.What did you do? I compared the temperature of water placed in the sun to water placed in the shade after 30 minutes. 2.What happened to the temperature of the water in the sunlight? Why? The temperature of water in the Sunlight cup became warmer than the water in the No Sunlight cup because when the water absorbed the sunlight’s radiant energy, it transfers to heat energy and heats the water. Difference
More Explorations Question: What happens to water and soil when they go in and out of sunlight? Predictions: Hint Materials per group (trial): soilwater 2 thermometers 2 same size clear containers
Procedures 1. Put a container of water and a container of soil in the shade. Measure the beginning temperature of both. Record. 2. Wait 15 minutes. Measure and record the temperature of both on the data table. 3. Take those two containers and place both in full sunlight. 4. Wait 15 minutes. Measure and record the temperature of both on the data table. 5. Take those two containers and place both back shade. 4. Wait 15 minutes. Measure and record the temperature of both on the data table.
More Explorations Data TimeWater Temperature Soil Temperature Shade 15 min. Sun 15 min. Shade 15 min.
Explain the Data More Explorations 1.What was the temperature difference of the soil in the shade and the soil in the sun? (Show your work.) 2. What was the temperature difference of the soil in the shade and the soil in the sun? (Show your work.) 3.Make a graph of your data. 4. Is this statement true or false: The sun heats the Earth? How do you know? 5. What are you wondering now?
Radiant Energy – Solar Energy Night Day As the Earth rotates on its axis, the side facing the sun absorbed the sunlight’s radiant energy, which transfers to heat energy and heats the Earth during daylight hours. As the Earth rotates, one side is turning away from the sun and stops receiving the sun’s radiant light energy and the transfer into heat energy, becoming cooler during night time.
You Tell Me??? Which of these pictures is receiving more light energy from the sun?... more heat energy from the sun? Why? 1 1. 2. 3.
REVIEW Questions 1.Give some examples of objects that produce heat. 2.Give some examples of objects that give off light and heat. 3.Why do people rub their hands together when they feel cold?
Build a Solar Oven You can use the sun's energy to heat up a tasty treat with this simple solar oven! Materials: Cardboard pizza box (the kind delivered pizza comes in) Box knife or scissors Aluminum foil Clear tape Plastic wrap (a heavy-duty or freezer zip lock bag will also work) Black construction paper Newspapers Ruler, or wooden spoon Click on link below for recipes ideas: Solar Oven Recipes PDF
What to do 1.Use a box knife or sharp scissors (with an adult’s help) to cut a flap in the lid of the pizza box. Cut along three sides, leaving about an inch between the sides of the flap and the edges of the lid. Fold this flap out so that it stands up when the box lid is closed. 2.Cover the inner side of the flap with aluminum foil so that it will reflect rays from the sun. To do this, tightly wrap foil around the flap, then tape it to the back, or outer side of the flap. 3.Use clear plastic wrap to create an airtight window for sunlight to enter into the box. Do this by opening the box and taping a double layer of plastic wrap over the opening you made when you cut the flap in the lid. Leave about an inch of plastic overlap around the sides and tape each side down securely, sealing out air. If you use a plastic bag, cut out a square big enough to cover the opening, and tape one layer over the opening. 4.Line the bottom of the box with black construction paper - black absorbs heat. The black surface is where your food will be set to cook. 5.To insulate your oven so it holds in more heat, roll up sheets of newspaper and place them on the bottom of the box. Tape them down so that they form a border around the cooking area. The newspaper rolls should make it so that the lid can still close, but there is a seal inside of the box, so air cannot escape. 6.
What to do – Part 2 6. The best hours to set up your solar oven are when the sun is high overhead - from 11 am to 3 pm. Take it outside to a sunny spot and adjust the flap until the most sunlight possible is reflecting off the aluminum foil and onto the plastic-covered window. Use a ruler to prop the flap at the right angle. You may want to angle the entire box by using a rolled up towel. 7. You can make toast by buttering a slice of bread, or sprinkling cheese on it, then letting the sun do the rest. Cooking a hot dog or making nachos with chips and cheese are also fun treats to make in your solar oven! It would also work great to heat up leftovers. So the paper at the bottom doesn't get dirty, put what you would like to cook on a clear plastic or glass plate. A pie plate would work well. 8.To take food out of the oven, open up the lid of the pizza box, and using oven mitts or potholders, lift the glass dish out of the oven. Few tips for having success with your solar oven: Move your solar oven when needed, so that it faces direct sunlight. You should be checking periodically on your oven, to make sure it is in the sun. Make sure that the foil-covered flap is reflecting light into the pizza box, through the plastic-covered window.
What's happening? The heat from the sun is trapped inside of your pizza box solar oven, and it starts getting very hot. Ovens like this one are called collector boxes, because they collect the sunlight inside. As it sits out in the sun, your oven eventually heats up enough to melt cheese, or cook a hot dog! How does it happen? Rays of light are coming to the earth at an angle. The foil reflects the ray, and bounces it directly into the opening of the box. Once it has gone through the plastic wrap, it heats up the air that is trapped inside. The black paper absorbs the heat at the bottom of the oven, and the newspaper make sure that the heat stays where it is, instead of escaping out the sides of the oven. Your solar oven will reach about 200° F on a sunny day, and will take longer to heat things than a conventional oven. Although this method will take longer, it is very easy to use, and it is safe to leave alone while the energy from the sun cooks your food. If you do not want to wait long to have a solar-cooked dish, try heating up something that has already been cooked, like leftovers, or a can of soup. Putting solid food in a glass dish and liquids in a heavy plastic zip lock bag works well. You can also pre-heat your oven by setting it in direct sun for up to an hour.