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Content Objective: PS3.A: Definitions of Energy The faster a given object is moving, the more energy it possesses. (4-PS3-1) Energy can be moved from place to place by moving objects or through sound, light, or electric currents. (4-PS3-2),(4-PS3-3) Performance Objective(s): Use evidence to construct an explanation relating the speed of an object to the 4energy of that object. [Assessment Boundary: Assessment does not include PS3quantitative measures of changes in the speed of an object or on any precise or 1. quantitative definition of energy. 4- Make observations to provide evidence that energy can be transferred from place PS3- to place by sound, light, heat, and electric currents. [Assessment Boundary: 2. Assessment does not include quantitative measurements of energy.] Ask questions and predict outcomes about the changes in energy that occur when 4objects collide. [Clarification Statement: Emphasis is on the change in the energy PS3due to the change in speed, not on the forces, as objects interact.] [Assessment 3. Boundary: Assessment does not include quantitative measurements of energy.] Energy How is energy transferred and conserved? Interactions of objects can be explained and predicted using the concept of transfer of energy from one object or system of objects to another. The total energy within a defined system changes only by the transfer of energy into or out of the system. PS3.A: DEFINITIONS OF ENERGY What is energy? That there is a single quantity called energy is due to the remarkable fact that a system’s total energy is conserved. Regardless of the quantities of energy transferred between subsystems and stored in various ways within the system, the total energy of a system changes only by the amount of energy transferred into and out of the system. At the macroscopic scale, energy manifests itself in multiple phenomena, such as motion, light, sound, electrical and magnetic fields, and thermal energy. Historically, different units were introduced for the energy present in these different phenomena, and it took some time before the relationships among them were recognized. Energy is best understood at the microscopic scale, at which it can be modeled as either motions of particles or as stored in force fields (electric, magnetic, gravitational) that mediate interactions between particles. This last concept includes electromagnetic radiation, a phenomenon in which energy stored in fields moves across space (light, radio waves) with no supporting matter medium. Motion energy is also called kinetic energy; defined in a given reference frame, it is proportional to the mass of the moving object and grows with the square of its speed. Matter at any temperature above absolute zero contains thermal energy. Thermal energy is the random motion of particles (whether vibrations in solid matter or molecules or free motion in a gas), this energy is distributed among all the particles in a system through collisions and interactions at a distance. In contrast, a sound wave is a moving pattern of particle vibrations that transmits energy through a medium. Electric and magnetic fields also contain energy; any change in the relative positions of charged objects (or in the positions or orientations of magnets) changes the fields between them and thus the amount of energy stored in those fields. When a particle in a molecule of solid matter vibrates, energy is continually being transformed back and forth between the energy of motion and the energy stored in the electric and magnetic fields within the matter. Matter in a stable form minimizes the stored energy in the electric and magnetic fields within it; this defines the equilibrium positions and spacing of the atomic nuclei in a molecule or an extended solid and the form of their combined electron charge distributions (e.g., chemical bonds, metals). Energy stored in fields within a system can also be described as potential energy. For any system where the stored energy depends only on the spatial configuration of the system and not on its history, potential energy is a useful concept (e.g., a massive object above Earth’s surface, a compressed or stretched spring). It is defined as a difference in energy compared to some arbitrary reference configuration of a system. For example, lifting an object increases the stored energy in the gravitational field between that object and Earth (gravitational potential energy) compared to that for the object at Earth’s surface; when the object falls, the stored energy decreases and the object’s kinetic energy increases. When a pendulum swings, some stored energy is transformed into kinetic energy and back again into stored energy during each swing. (In both examples energy is transferred out of the system due to collisions with air and for the pendulum also by friction in its support.) Any change in potential energy is accompanied by changes in other forms of energy within the system, or by energy transfers into or out of the system. Electromagnetic radiation (such as light and X-rays) can be modeled as a wave of changing electric and magnetic fields. At the subatomic scale (i. e., in quantum theory), many phenomena involving electromagnetic radiation (e.g., photoelectric effect) are best modeled as a stream of particles called photons. Electromagnetic radiation from the sun is a major source of energy for life on Earth. The idea that there are different forms of energy, such as thermal energy, mechanical energy, and chemical energy, is misleading, as it implies that the nature of the energy in each of these manifestations is distinct when in fact they all are ultimately, at the atomic scale, some mixture of kinetic energy, stored energy, and radiation. It is likewise misleading to call sound or light a form of energy; they are phenomena that, among their other properties, transfer energy from place to place and between objects. Grade Band Endpoints for PS3.A By the end of grade 2. [Intentionally left blank.] By the end of grade 5. The faster a given object is moving, the more energy it possesses. Energy can be moved from place to place by moving objects or through sound, light, or electric currents. (Boundary: At this grade level, no attempt is made to give a precise or complete definition of energy.) Unit: Definitions of Energy Text: Chapter 12 pages 350-353, Chapter 14 pages 406-407 and 416-417, Chapter 15 pages 436-449 https://www.teachengineering.org/view_lesson.php?url=collection/cub_/lessons/cub_energy2/cub_ener gy2_lesson01.xml Day One: Engage- How do we get energy? Explore- Energy Stations “What is energy?” Engage- Ask students to complete an exercise circuit in the room for five minutes, one minute at each station. Station one is squats, Station two is jumping jacks, Station three is windmills, Station four is arm circles, and Station five is jogging in place. After the circuit is complete, ask students how they feel. Ask them to talk about how and why they were able to do hard body work for these five minutes. Hopefully, at least one student will mention energy. “How do animals get energy?” Write student responses on the board and discuss how sleep and food are important for us to have energy, but why? How do we get energy and what is it? Explore- Students will complete five stations exploring energy and its definition: the ability to do work or cause change. At each station, they will complete the activity and discuss the how the definition of energy applies to each activity. Station One (Teacher Demonstrated)- Burning Peanut https://www.teachengineering.org/view_activity.php?url=collection/cub_/activities/cub_energy2/cub _energy2_lesson01_activity1.xml Peanut Calorie Demo (conduct as a class; 5 minutes) 1. Have students sit in a circle a few feet away from this demo. 2. Hold your hand over the flame of a Bunsen burner (not too close!) (or use a candle and matches). Can you feel the heat? copyright 3. Hold a peanut with tongs and light it using a Bunsen burner (or a candle or a match). 4. Hold the peanut until the flame has burned it. 5. Have students count the number of seconds it takes the peanut flame to go out. Explain to them that the peanut is burning fat calories. 6. You may want to use the peanut to heat a small test tube of water, or try burning a different type of nut. (With a different type of nut, the time changes due to the change in amount of fat calories.) 7. Class discussion. As we take in food, our bodies work as furnaces to burn and release energy. When designing sports foods and beverages, engineers study how much energy food items have and how much time it takes a body to burn those calories. Station Two- Tin Can Telephone Students will get into partners and share a secret message through the tin can telephone and write down what they hear. Station Three- The Coiling Snake https://www.teachengineering.org/view_activity.php?url=collection/cub_/activities/cub_energy2/cub _energy2_lesson01_activity1.xml 1. Divide the class into teams of two or three students each. 2. Have students in each team cut their Coiling Snake Templates, making sure to cut along all the lines. 3. Draw and cut a forked tongue from red construction paper. 4. Glue the tongue onto the snake. 5. Poke a hole in the snake's head or tail; using a hole punch works best. copyright 6. Cut a piece of string (or thread) about 30 cm (1 foot) long. 7. Tie the string to the snake's head or tail, and knot it. 8. Hold the snake by the string over a candle or light bulb. 9. As the light bulb heats up, the snake should spin. 10. Explanation: When the candle burns, two forms of energy are released, heat and light energy. The heat causes the air to rise up, which in turn makes the snake spin around. (The snake does not move up because the coiled shape of the snake allows the heat to rise through the middle and spin the snake.) 11. Class discussion: The energy we need comes from the food we eat. The energy required to turn the pedals of a bicycle comes from the person riding the bicycle. Cars and trucks get their energy from gasoline. Some homes are heated using oil or natural gas or firewood. When designing heating and cooling systems, engineers study thermal energy and how it creates air movement. They place heat vents and radiators low, near the floor because they know that hot air rises. As hot air rises it mixes with the existing room air, preventing "cold" spots and making the space more comfortable. The same is true for cool air vents that are placed high, near the ceiling. The cool air sinks, evenly mixing with the existing room air. Station Four- Mason Jar Bowling Students will roll mason jars filled with flower down a binder ramp to try and knock over empty 20 oz. bottles. Station Five- Heat it Up Students will heat a pan of water using a heat lamp and monitor the temperature over time. Students will complete the reflection questions for each station as they rotate. Day Two: Explore- Energy Stations “What is energy?” Students will complete their energy stations and questions today. Day Three: Explain- Energy Stations “What is energy?” Elaborate- BrainPop Energy, Potential and Kinetic Energy Evaluate- Kinetic or Potential Energy Explain: Discuss each station and what observations students were able to make about how the activity demonstrated the definition of energy. Explain that each station energy was causing change. The heat from the hot plate caused the peanut to burn fat and release stored energy, kind of like when we exercise. The sound waves from your voice were causing the string to vibrate and carry the sound from one can to another. The heat from the lamp was causing the snake to rise and spin. The mason jars stored energy at the top of the ramp and transferred it to the bottles to knock them down. Finally, the heat from the lamp caused the water to heat up thereby making the temperature on the thermometer increase. These all show how energy can be transferred through heat, sound, and motion to cause change. Elaborate: Share the BrainPop on Energy and discuss how each station demonstrated potential and kinetic energy. Evaluate: Students will do a matching activity at their tables to determine if each picture is demonstrating potential or kinetic energy. Students can use pages 448 and 449 to help them determine which are potential and which are kinetic. Day Four: Engage- Human Bowling Explain- Illustration Explore- Force, Motion, and Energy Engage: Ask students if they think they would be able to push Mr. Grissom over if he was standing next to them. Do they think they could know him over if they got a running start??? Well, we aren’t actually going to knock Mr. Grissom over, but we could try another approach. Using a rolling office chair and butcher block paper, demonstrate that the more energy there is in pushing an object the more force or energy it will carry with it. Explore: Students will read about force and motion using the Lesson 2 summary sheet and checkpoint questions. Explain: At the bottom of the page, students must illustrate an example of how adding more speed to an object gives it more energy. There is an example in the text of a bicyclist, which will help give students an idea of what to choose. Underneath the illustration they must explain how the object gains speed and how they know it has more energy. Days Five and Six: Evaluate- Angry Birds Project (See attached packet for plans) Day Seven: Student share and quiz * We will take a quiz at this point to make sure students understand the basic concepts of energy, but we will not test these concepts until after the next unit.