7 th Grade Science Unit: The Magic of Energy: A Disappearing Act? Unit Snapshot

Transcription

1 7 th Grade Science Unit: The Magic of Energy: A Disappearing Act? Unit Snapshot Topic: Conservation of Mass and Energy Grade Level: 7 Duration: 9 days Summary: The following activities engage students in exploring energy transfer and transformations as they relate to the conservation of energy in both open and closed systems through investigation, testing, and experimentation. CLEAR LEARNING TARGETS I can statements explain that energy can be transformed or transferred but is never lost. investigate how energy can be transferred into or out of an open system. Activity Highlights and Suggested Timeframe Day 1 Engagement: The objective of this activity is to engage students and formatively assess their knowledge related energy forms and transformation of energy through a quick-write and Newton s cradle demonstration. Day 2 Days 3-4 Days 5-7 Day 8 and on-going Day 9 Exploration: The objective of the following activities is to give students the opportunity to work with and begin to develop a basic understanding of thermal energy transfer in an open-system through an exploratory activity involving water, and follow-up scenario-based example for reinforcement. Explanation: The objective of the following activities is to give students the opportunity to develop their knowledge of potential and kinetic energy relationships in regards to conservation of energy through CPO Investigation 6A and/or an explore learning GIZMO: Roller Coaster Physics. Elaboration: The objective of the following activities is to give students the opportunity to gain deeper understanding of energy transformations through a student centered inquiry investigation involving light bulb energy output and efficiency comparisons. Evaluation: Formative and summative assessments are used to focus on and assess student knowledge and growth to gain evidence of student learning or progress throughout the unit, and to become aware of students misconceptions related to the conservation of energy. A teacher-created short cycle assessment will be administered at the end of the unit to assess all clear learning targets (Day 8). Extension/Intervention: Using data based on the results of evaluation and shortcycle assessments, provide intervention and/or extension activities for students. 1

2 LESSON PLANS NEW LEARNING STANDARDS: 7.PS.2 Energy can be transformed or transferred but is never lost. When energy is transferred from one system to another, the quantity of energy before transfer equals the quantity of energy after transfer. When energy is transformed from one form to another, the total amount of energy remains the same. Note: Further discussion of energy transformation is addressed at the high school level. SCIENTIFIC INQUIRY and APPLICATION PRACTICES: During the years of grades K-12, all students must use the following scientific inquiry and application practices with appropriate laboratory safety techniques to construct their knowledge and understanding in all science content areas: Asking questions (for science) and defining problems (for engineering) that guide scientific investigations Developing descriptions, models, explanations and predictions. Planning and carrying out investigations Constructing explanations (for science) and designing solutions (for engineering)that conclude scientific investigations Using appropriate mathematics, tools, and techniques to gather data/information, and analyze and interpret data Engaging in argument from evidence Obtaining, evaluating, and communicating scientific procedures and explanations *These practices are a combination of ODE Science Inquiry and Application and Frame-work for K-12 Science Education Scientific and Engineering Practices COMMON CORE STATE STANDARDS for LITERACY in SCIENCE: *For more information: CCSS.ELA-Literacy.RST Follow precisely a multistep procedure when carrying out experiments, taking measurements, or performing technical tasks. CCSS.ELA-Literacy.RST Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 6 8 texts and topics. CCSS.ELA-Literacy.RST Integrate quantitative or technical information expressed in words in a text with a version of that information expressed visually (e.g., in a flowchart, diagram, model, graph, or table). STUDENT KNOWLEDGE: Prior Concepts Related to Energy Transfer PreK-2: Sound is produced by vibrating objects. The sun is the principal source of energy and affects the warming or cooling of Earth (ESS). Weather changes occur due to changes in energy (ESS). Plants get energy from sunlight and animals get energy from plants and other animals (LS). Grades 3-5: Objects with energy have the ability to cause change. Energy can transfer from one location or object to another and can be transformed from one form to another (e.g., light, sound, heat, electrical energy, magnetic energy. Earth s resources can be used for energy (ESS). Sunlight is transformed by producers into energy that organisms can use and pass from organism to organism (LS). Grade 6: There are two forms of energy: kinetic and potential. Energy can transform from one form to another. Thermal energy is due to random motion of the particles of a substance. Future Application of Concepts Grade 8: Gravitational, chemical and elastic potential energy are explored. High School: Waves are further explored as a method of transferring energy. Basic formulas are used to perform calculations with energy. Work is a method of and power is a rate of energy transfer. 2

3 MATERIALS: Engage Computer/Internet/Projector Newton s Cradle or CPO Pendulum Explore CPO Textbook Spoons Hot Water; Room Temp. Water Glass Beakers Thermometers WS: Where Did the Energy Go? WS: Cooling Curves VOCABULARY: Primary Closed System Energy Transfer (3,6) Energy Transformation (3,6) Open System Secondary Conservation of Energy Kinetic Energy (6) Potential Energy (6) Thermal Energy (3,4,6) Explain Computers/Laptops CPO Lab 6A Equipment (roller coaster) Index Cards WS: GIZMO Roller Coaster Physics WS: CPO Investigation 6A Elaborate Incandescent Light Bulbs Compact Fluorescent Light Bulbs Lamp Bases/Clamp Lights Thermometers Timers Calculators WS: Light Bulb or Heat Bulb? SAFETY ADVANCED PREPARATION ENGAGE (1 day) (What will draw students into the learning? How will you determine what your students already know about the topic? What can be done at this point to identify and address misconceptions? Where can connections be made to the real world?) All lab safety rules and procedures apply. Reserve computers for on-line simulation GIZMO activity Gather and prepare materials for Newton s Cradle/pendulum demo, water activity, CPO Investigation lab 6A: Energy Transformations on a Roller Coaster, and Light bulb or heat bulb? activity. Objective: The objective of this activity is to engage students and formatively assess their knowledge related energy forms and transformation of energy through a quick-write and demonstration. What is the teacher doing? Energy Transformations Intro (Day 1) Show the video: Science and the City: Energy [4:54] and/or Testing the Law of Conservation of Energy [1:21] Facilitate a quick write about the information learned during the video clip such as the various forms of energy. Discuss the law of conservation of energy Energy cannot be What are the students doing? Energy Transformations Intro (Day 1) 1. Show the video: Science and the City: Energy [4:54] and/or Testing the Law of Conservation of Energy [1:21] -Perform a quick write describing all of the energy transformations in the video(s). 3

4 created or destroyed (Students should be familiar with law of conservation of mass and can relate that knowledge to energy) Newton s Cradle Demo: Using a Newton s Cradle model, the CPO pendulum on a string setup, or this animation ( nek/scenario/newton.htm) Ask students the following questions: If energy cannot be destroyed, then why does the pendulum eventually come to a stop? Explain where the energy goes? Answer: Because this is an open system, the energy is transformed into other types of energy such as sound (in Newton s cradle when the balls hit each other), heat due to friction (air resistance). 2. Students observe the demo and discuss teacher-led questions. Objective: The objective of the following activities is to give students the opportunity to work with and begin to develop a basic understanding of thermal energy transfer in an open-system through an exploratory activity involving water, and follow-up scenariobased example for reinforcement. EXPLORE (1 day) (How will the concept be developed? How is this relevant to students lives? What can be done at this point to identify and address misconceptions?) What is the teacher doing? Thermal Energy Transformation Using Water (Day 2) Facilitate a close reading of pp in the CPO textbook. Optional: Show or Play the Conservation of Energy Song by Mr. Parr - h?v=k60jgjfv8ou Where Did the Energy Go? Activity: -This can be completed as a student activity or teacher demo. Distribute WS: Where Did the Energy Go? Fill a beaker with room What are the students doing? Thermal Energy Transformation Using Water (Day 2) 1. Using the CPO textbook pp , students perform a close reading. 2. Students complete Where Did the Energy Go? activity and WS. 4

5 temperature water and measure the exact temperature. Heat a beaker of water, and measure the temperature. Place a spoon full of the hot water into the large beaker of room temperature water. Measure the temperature of the large beaker. Continue to add a spoonful of water and measure the large beaker temperature until 10 spoonful s of water and have been added and measurements taken. Distribute and facilitate: Cooling Curves WS 3. Students complete the Cooling Curves WS Objective: The objective of the following activities is to give students the opportunity to develop their knowledge of potential and kinetic energy relationships in regards to conservation of energy through explore learning GIZMO: Roller Coaster Physics and/or CPO Investigation 6A What is the teacher doing? GIZMO: Roller Coaster Physics (Priorknowledge Questions, Warm-up, and Part C Only) and/or CPO Lab 6A: Energy transformations on a Roller Coaster (Days 3-4) What are the students doing? GIZMO: Roller Coaster Physics (Priorknowledge Questions, Warm-up, and Part C Only) and/or CPO Lab 6A: Energy transformations on a Roller Coaster (Days 3-4) EXPLAIN (2 days) (What products could the students develop and share? How will students share what they have learned? What can be done at this point to identify and address misconceptions?) Distribute student Roller Coaster Physics WS. This lesson can be completed as a whole group class instruction with teacher facilitation or if possible, students working individually or partners on computers or laptops. Other Lesson materials are available on the website. If you are unfamiliar with GIZMO s or do not know your username/password, call the CCS science x5297. Show the on-line simulation of a rollercoaster showing changes in potential and kinetic energy: g/asset/mck05_int_rollercoaster 1. Students work individually, with a partner, or as a class to discover how potential energy, kinetic energy, and total energy are related. 2. Students predict what will happen to the kinetic and potential energy of the simulated rollercoaster car as is travels on the track and draw a pie chart at each position to show the relationship between the potential and kinetic energy. 5

6 -Run the simulation one step at a time, asking students to predict what will happen to the kinetic and potential energy and draw a pie chart at that position to show the relationship between the potential and kinetic energy. (see WS) and/or Part I: Distribute CPO Lab 6A WS and facilitate CPO Lab 6A: Energy Transformations on a Roller Coaster. -The focus should be on the relationship between potential energy, kinetic energy, and total energy (conservation of energy) Part II: Distribute 5 index cards to each group. Each group should create 5 bar graphs for 5 different places on their roller coaster showing the relationship between potential and kinetic energy. -See Teacher Activity Page for more information. 3. Students then view the simulation step by step. Students should discover that potential energy and kinetic energy are inverses. This reinforces the idea of conservation energy and transformations. and/or 4. Part I: Complete CPO Lab 6A: Energy Transformations on a Roller Coaster. 5. Part II: Students work in groups to create 5 bar graphs on index cards showing the relationship of potential and kinetic energy for 5 different places on the rollercoaster structure. 6. Students record the correct answers and placements on their WS, but then mix up the index cards and trade with another group. Each group must try to figure out the correct placement of the index cards on the roller coaster structure and defend their choices. ELABORATE (3 days) (How will the new knowledge be reinforced, transferred to new and unique situations, or integrated with related concepts?) Objective: The objective of the following activities is to give students the opportunity to gain deeper understanding of energy transformations through a student centered inquiry investigation involving light bulb energy output and efficiency comparisons. What is the teacher doing? Light Bulb or Heat Bulb?: Energy Transformations in a Light bulb (Days 5-7) Review the energy transformation in a light bulb Electrical energy transforms into heat(thermal) and light. Ask students, to think about if all light bulb transformations are the same? What are the students doing? Light Bulb or Heat Bulb?: Energy Transformations in a Light bulb (Days 5-7) 1. Students conduct an investigation to test and compare the amount of energy (thermal/light) dissipated in various bulbs, and to explain how the energy transformation takes place in various bulbs. (See student WS). 6

7 When energy transfers to a large system, it may be difficult to measure the effects of the added energy. Dissipated energy (energy that is transformed into thermal energy and released into the surroundings) is difficult or impossible to recapture. Some systems, such as certain light bulbs, dissipate less energy than others, leaving more energy to use. It is suggested to facilitate as students develop their own investigation to test and compare the amount of energy (thermal/light) dissipated in various bulbs, and to explain how the energy transformation takes place in various bulbs. See Teacher Activity Sheet for more information and a sample WS. EVALUATE (on-going) (What opportunities will students have to express their thinking? When will students reflect on what they have learned? How will you measure learning as it occurs? What evidence of student learning will you be looking for and/or collecting?) Objective: The objective of the assessments is to focus on and assess student knowledge and growth to gain evidence of student learning or progress throughout the lesson, and to become aware of students misconceptions related to the transformation of energy in open and closed systems. Formative How will you measure learning as it occurs? Consider developing a teacher-created formative assessment. 1. Newton s Cradle Demo/pendulum and discussion can formatively assess the students knowledge of open and closed systems as they relate to energy transformations. 2. Where Did the Energy Go? Activity can assess the students ability to explain thermal energy transfer. Summative What evidence of learning will demonstrate to you that a student has met the learning objectives? 1. Light Bulb or Heat Bulb activities can be used to assess the students ability to apply knowledge of energy transformations into a large system through comparisons of various light bulb systems. 2. Teacher-created short cycle assessment will assess all clear learning targets (Day 8). 3. On-line simulations and CPO Lab 6A can assess student knowledge related to potential energy and kinetic energy transformations. 7

8 EXTENSION/ INTERVENTION (1 day or as needed) EXTENSION 1. In addition to CFL s and IL s for the Light bulb or Heat Bulb? Lessons, students test and compare various other light bulb types LED s, various wattages, UV bulbs, colored light bulbs, black light. 2. Have students create their own energy transformation diagrams showing examples of various transformations 3. Jason Project: Roller Coaster Creator (on-line simulation game): content/content/digitallab/4859/mi sc_content/public/coaster.html -Coaster Creator: Post-lab - ges/files/126544/coaster_creator_p ostlab_worksheet.pdf INTERVENTION 1. related videos 2. Energy Skate Park, an interactive simulation from PhET, demonstrates conservation of energy: ation/energy-skate-park -Teaching ideas and tips can be found on the website. 3. Science NetLinks provides various activities to explore energy through some Internet resources as well as engaging in some hands-on activities: converting-energy/ COMMON MISCONCEPTIONS Energy is truly lost in many energy transformations. If energy is conserved, why are we running out of it? Energy can be changed completely from one form to another (no energy losses). Things use up energy. Energy is a thing. The terms energy and force are interchangeable. Energy often disappears and is lost. Energy is a type of matter or substance that can flow like a liquid. Strategies to address misconceptions: Misconceptions can be addressed through the use of Discover Ed ( video clips, on-line simulations, lab investigations, as well as through the use models. DIFFERENTIATION Lower-level: For the Investigation Lab 6A, and other activities, consider grouping students flexibly by shared interest, topic or ability and provide clear concise directions. Consider offering mini-lessons to support learning. Create various assessments in order to assess student learning. Consider allowing students to draw or verbally explain various transformations. Consider performing read-alouds for any reading activity. Higher-Level: Consider having students create their own investigations for testing energy transformations in light bulbs instead of the premade lab. Consider offering extension activities. 8

9 Strategies for meeting the needs of all learners including gifted students, English Language Learners (ELL) and students with disabilities can be found at the following sites: ELL Learners: Gifted Learners: Students with Disabilities: load.aspx?documentid= Textbook Resources: CPO Physical Science Textbook: Chapter 6.1: Energy and the Conservation of Energy pp Websites: Energy Skate Park, an interactive simulation from PhET, demonstrates conservation of energy: Discovery Ed: Science and the City: Energy [4:54] Roller Coaster Physics [6:45] Skiing and Energy Transformation [3:47] The Law of Conservation of Energy [4:35] Human Energy Transformations [3:21] Physical Energy Transformations [2:13] ADDITIONAL RESOURCES Literature: Viegas, Jennifer. (2005). Kinetic and Potential Energy: Understanding Changes within Physical Systems. Rosen Publishing Group. Pinna, Simon. (2007). Transfer of Energy. Gareth Stevens Publishing. Mullins, Matt. (2012). Force and Energy. Scholastic/Children s Press. Claybourne, Anna. (2008). Force and Energy. Raintree Publishing. Movies/Videos: Force and Energy 5 Videos. (2006). Schlessinger Media. [v. 01.] All about heat -- [v. 02.] All about the conservation of energy -- [v. 03.] All about the transfer of energy -- [v. 04.] All about the uses of energy -- [v. 05.] What is energy? Exploring Energy DVD. (2008). Visual Learning Company. Learn the difference between potential energy and kinetic energy, and how to demonstrate different forms of energy, including mechanical, thermal, chemical, electromagnetic, sound, and nuclear energy. 9

10 Teacher Page Energy Transformation Intro 1. video: Science and the City: Energy [4:54] and/or Testing the Law of Conservation of Energy [1:21] 2. Newton s Cradle Demo: Using a Newton s Cradle model, CPO pendulum on a string set-up, or this animation ( students the following questions: o If energy cannot be destroyed, then why does the pendulum eventually come to a stop? o Did it disappear? o Explain where the energy goes. -Answer: Because this is an open system, the energy is transformed into other types of energy such as sound (in Newton s cradle when the balls hit each other), heat due to friction (air resistance and when the balls hit each other). 10

11 Name Date Period Where did the energy go? Directions: Fill a large beaker with room temperature water and measure the exact temperature. Heat a beaker of water, and measure the exact temperature. Place a spoon full of the hot water into the large jar of room temperature water. Measure the temperature of the large beaker of water. Continue to add a spoonful of hot water and re-measure the large beaker of water, until you have added 10 spoonful s of hot water. Record your data: Hot Water Room Temp. Water Spoonful s Questions: 1. Based on your temperature data, summarize what occurred. Temp ( C) _ 2. What type of energy does the water in the spoon have at the beginning of the experiment? 3. Where did the energy go? Explain. What is the evidence? _ 4. Is this considered an open-system or closed-system? Explain. _ 11

12 Name Date Period Cooling Curves of Water Experimental Description Two identical beakers with exactly the same amount of warm water were prepared. The first beaker was allowed to cool by sitting in a classroom with an air temperature of 23 C. The second beaker was placed in a large bucket of ice water at 0 C. Draw a diagram of Beaker #1 system Draw a diagram of Beaker #2 system The temperature of each was measured every minute for 45 minutes. The data is shown below. 12

13 Name Date Period Questions: 1) Based on the graph, what happened to the temperature of each beaker of water and Why? Beaker #1: Beaker #2: 2) Based on the graph, which beaker of water starts off at higher temperature? 3) Based on the graph, which beaker of water ends up at a higher temperature and Why? 4) Based on the graph, after 10 minutes, what are the temperatures of the two beakers of water? Beaker #1: Beaker #2: 5) Are Beakers 1and 2 considered open systems or closed systems? Explain. 6) Based on what you know about energy transfer in Beaker #2, what do you predict would begin to happen to the ice? 13

14 Name Date Period Where did the energy go? TEACHER KEY Directions: Fill a large beaker with room temperature water and measure the exact temperature. Heat a beaker of water, and measure the exact temperature. Place a spoon full of the hot water into the large jar of room temperature water. Remeasure the temperature of the large beaker of water. Continue to add a spoonful of water and re-measure the large beaker of water, until you have added 10 spoonful s of hot water. Record your data: Spoonful s Temp ( C) Hot Water 3 4 Data will Vary 5 Room Temp. 6 Water Questions: Based on your temperature data, summarize what occurred. _ The temperature of the water in the beaker increased as more spoonful s of _ water were added. _ 2. What type of energy does the water in the spoon have before it is placed in the beaker of room temperature water? Thermal Energy 3. Where did the energy go? Explain. What is the evidence? _ The energy of the hot water, was transferred to the room temperature water, _ This is supported by increasing the temperature of the water in the beaker. _ 4. Is this considered an open-system or closed-system? Explain. _ This is considered an open-system, because energy is being transferred from _ an outside source. _ 14

15 Name Date Period Cooling Curves of Water TEACHER KEY Experimental Description Two identical beakers with exactly the same amount of warm water were prepared. The first beaker was allowed to cool by sitting in a classroom with an air temperature of 23 C. The second beaker was placed in a large bucket of ice water at 0 C. Draw a diagram of Beaker system #1 Draw a diagram of Beaker system #2 23 C 0 C The temperature of each was measured every minute for 45 minutes. The data is shown below. 15

16 Name Date Period Questions: - TEACHER KEY 1) Based on the graph, what happened to the temperature of each beaker of water and Why? Beaker #1: Temperature decreased because the energy is transferred from the water to the air. Beaker #2: Temperature decreased because the energy is transferred from the water to the ice and air. 2) Based on the graph, which beaker of water starts off at higher temperature? Neither They were the same temperature. 3) Based on the graph, which beaker of water ends up at a higher temperature and Why? Beaker # 1 ends up at a higher temperature because less energy is transferred into the air, than the ice. 4) Based on the graph, after 10 minutes, what are the temperatures of the two beakers of water? Beaker #1 = 40 C Beaker #2 = 26 C 5) Are Beakers 1and 2 considered open systems or closed systems? Explain. Beakers 1 and 2 are considered open systems, because the energy interacts with the environment surrounding the beakers instead of being contained within the beaker. 6) Based on what you know about energy transfer in Beaker #2, what do you predict would begin to happen to the ice? Because the ice is receiving thermal energy from the water, the ice will increase in temperature and melt. 16

17 Name: Date: Student Exploration: Roller Coaster Physics Vocabulary: friction, gravitational potential energy, kinetic energy, momentum, speed Prior Knowledge Questions (Do these BEFORE using the Gizmo.) An object s momentum reflects how easy it is to stop. Objects with greater momentum are harder to stop and can also inflict more damage when they collide with other objects. 1. Which do you think has more momentum, a moving car or a moving train? 2. The speed of an object is how fast it is moving. Which has more momentum, a car with a speed of 20 km/h (kilometers per hour) or a car moving at 100 km/h? 3. What are the two factors that affect an object s momentum? Gizmo Warm-up The Roller Coaster Physics Gizmo shows a toy car on a track that leads to an egg. You can change the track or the car. For the first experiment, use the default settings (Hill 1 = 70 cm, Hill 2 = 0 cm, Hill 3 = 0 cm, 35-g car). 1. Press Play ( ) to roll the 35-gram toy car down the track. Does the car break the egg? 2. Click Reset ( ). Raise Hill 1 to 100 cm, and click Play again. Does the car break the egg? 3. Click Reset. Lower Hill 1 back to 70 cm and select the 50-gram toy car. Click Play. Does the 50-gram car break the egg? 4. What factors determine whether the car will break the egg? 17

18 Name: Date: Activity C: Energy on a roller coaster Get the Gizmo ready: Click Reset. Set Hill 1 to 100 cm, and Hill 2 and 3 to 0 cm. Select the 50-g car. Question: How is energy expressed in a moving roller coaster? 1. Observe: Turn on Show graph and select E vs t to see a graph of energy (E) versus time. Click Play and observe the graph as the car goes down the track. Does the total energy of the car change as it goes down the hill? 2. Experiment: The gravitational potential energy (U) of a car describes its energy of position. Click Reset. Set Hill 3 to 99 cm. Select the U vs t graph, and click Play. A. What happens to potential energy as the car goes down the hill? B. What happens to potential energy as the car goes up the hill? 3. Experiment: The kinetic energy (K) of a car describes its energy of motion. Click Reset. Select the K vs t (kinetic energy vs. time) graph, and click Play. A. What happens to kinetic energy as the car goes down the hill? B. What happens to kinetic energy as the car goes up the hill? 4. Compare: Click Reset. Set Hill 1 to 80 cm, Hill 2 to 60 cm, and Hill 3 to 79 cm. Be sure the 50-g toy car is selected, and press Play. Sketch the U vs t, K vs t, and E vs t graphs below. 5. Draw conclusions: Based on the graphs, how are potential energy, kinetic energy, and total energy related to one another? 18

19 Name: Date: Energy in a Roller Coaster Simulation: 1 Directions: For each location on the roller coaster, show the relationship between potential and kinetic energy by completing a pie chart showing your predicted amounts of potential energy and kinetic energy. 0% PE 0% KE Example Use evidence from the diagram to explain and support the claim that the total amount of energy remains the same when energy is transformed from one form to another. 19

20 Roller Coaster Physics Answer Key Vocabulary: friction, gravitational potential energy, kinetic energy, momentum, speed Prior Knowledge Questions (Do these BEFORE using the Gizmo.) [Note: The purpose of these questions is to activate prior knowledge and get students thinking. Students are not expected to know the answers to the Prior Knowledge Questions.] An object s momentum reflects how easy it is to stop. Objects with greater momentum are harder to stop and can also inflict more damage when they collide with other objects. 4. Which do you think has more momentum, a moving car or a moving train? The train 5. The speed of an object is how fast it is moving. Which has more momentum, a car with a speed of 20 km/h (kilometers per hour) or a car moving at 100 km/h? The 100 km/h car 6. What are the two factors that affect an object s momentum? Mass (or weight) and speed Gizmo Warm-up The Roller Coaster Physics Gizmo shows a toy car on a track that leads to an egg. You can change the track or the car. For the first experiment, use the default settings (Hill 1 = 70 cm, Hill 2 = 0 cm, Hill 3 = 0 cm, 35-g car). 5. Press Play ( ) to roll the 35-gram toy car down the track. Does the car break the egg? No 6. Click Reset ( ). Raise Hill 1 to 100 cm, and click Play again. Does the car break the egg? Yes 7. Click Reset. Lower Hill 1 back to 70 cm and select the 50-gram toy car. Click Play. Does the 50-gram car break the egg? Yes 8. What factors determine whether the car will break the egg? The mass of the car and the speed of the car affect whether the car will break the egg. The speed of the car is determined by the height of the hill. 20

21 Activity C: Energy on a roller coaster Get the Gizmo ready: Click Reset. Set Hill 1 to 100 cm, and Hill 2 and 3 to 0 cm. Select the 50-g car. Question: How is energy expressed in a moving roller coaster? 6. Observe: Turn on Show graph and select E vs t to see a graph of energy (E) versus time. Click Play and observe the graph as the car goes down the track. Does the total energy of the car change as it goes down the hill? No, it stays the same 7. Experiment: The gravitational potential energy (U) of a car describes its energy of position. Click Reset. Set Hill 3 to 99 cm. Select the U vs t graph, and click Play. C. What happens to potential energy as the car goes down the hill? It decreases D. What happens to potential energy as the car goes up the hill? It increases 8. Experiment: The kinetic energy (K) of a car describes its energy of motion. Click Reset. Select the K vs t (kinetic energy vs. time) graph, and click Play. C. What happens to kinetic energy as the car goes down the hill? It increases D. What happens to kinetic energy as the car goes up the hill? It decreases 9. Compare: Click Reset. Set Hill 1 to 80 cm, Hill 2 to 60 cm, and Hill 3 to 79 cm. Be sure the 50-g toy car is selected, and press Play. Sketch the U vs t, K vs t, and E vs t graphs below. 10. Draw conclusions: Based on the graphs, how are potential energy, kinetic energy, and total energy related to one another? Answers will vary. [The total energy of the car is equal to the sum of its gravitational potential energy and its kinetic energy. As the car goes down a hill, gravitational potential energy is converted to kinetic energy, but the total energy of the car remains the same. As the car goes up a hill, kinetic energy is converted to gravitational potential energy.] 21

22 Name: Date: Teacher Answer Key Energy in a Roller Coaster Simulation: 0% PE 0% KE stopped Example 100% PE 0% KE 1 Directions: For each location on the roller coaster, show the relationship between potential and kinetic energy by completing a pie chart showing your predicted amounts of potential energy and kinetic energy. 2 0% PE 100% KE % PE 85% KE 5 65% PE 55% KE 6 0% PE 100% KE 0% PE 100% KE Use evidence from the diagram to explain and support the claim that the total amount of energy remains the same when energy is transformed from one form to another. As energy in transformed throughout the rollercoaster ride between kinetic and potential energy, the total energy remains at 100%. For example, the 100%potential energy at position 1, is completely transformed into 100% kinetic energy at position 2. 22

23 Investigation 6A Energy Transformations on a Roller Coaster 6A Energy Transformations on a Roller Coaster Where does the marble move the fastest, and why? To pedal your bicycle up a hill, you have to work hard to keep the bicycle moving. However, when you start down the other side of the hill, you can coast! In this investigation, you will see how a marble s speed changes as it moves up and down Materials CPO Roller Coaster steel marble CPO Timer and photogates meter stick Physics stand ASet up the roller coaster 1. Attach the roller coaster to the fifth hole from the bottom of the stand. 2. Place the marble against the starting peg and let it roll down the track. 3. Watch the marble roll along the track. Where do you think it moves the fastest? BA hypothesis a. Think about the seven places in the diagram. Where do you think the marble is moving the fastest? Choose one of the seven places and write down why you think that will be the fastest place. _ 23

24 CTesting your idea 1. Set the timer in interval mode and plug a photogate into input A. 2. Measure the time it takes the marble to roll through the photogate at each of the seven places. Be sure the photogate is pushed up against the bottom of the track. 3. The speed of the marble is its diameter divided by the time it takes to pass through the photogate. Find the speed of the marble at each position by dividing the diameter of the marble (1.9 cm) by the time through photogate A. Table 1: Speed of the Marble Position Distance (cm) Time A (s) Speed (cm/s) DStop and think a. Which position was fastest? b. Propose an explanation for why that place was fastest. c. The marble has more potential energy at the top of the roller coaster than at the bottom. What happens to this energy?

25 Investigation 6A Energy Transformations on a Roller Coaster d. It takes energy to increase the marble s speed. Where does this energy come from? EEnergy and change 1. Measure the speed and height of the marble every 10 cm along the roller coaster. Table 2: Speed and height data Position (cm) Height (cm) Time A (s) Speed (cm/s) a. Make a graph with the height on the y-axis and the position on the x-axis. Example

26 b. Scale the right hand side so you can plot speed on the same graph. Use the example in the diagram. d. What does the graph tell you about the relationship between speed and height? c. Explain the graph in terms of potential energy, kinetic energy, and total energy.

27 CPO Lab Investigation Lab 6A Teacher Pages Part I: Digital Lab sheets, directions, and teacher answer key can be found in the CPO Textbook Resource Materials - Teacher Resource CD. Part II: This activity is adapted from the New Learning Standards: Vision Into Practice Classroom Examples. Distribute 4 index cards to each group. Each group should pick 4 positions on the roller coaster, create 4 bar graphs for each of 4 different positions showing the relationship between potential and kinetic energy. Example:

28 TEACHER KEY - Index Card examples: Section 1 Section Potential Energy Kinetic Energy Potential Energy Kinetic Energy Section 5 Section Potential Energy Kinetic Energy Potential Energy Kinetic Energy Next, have each group mix up their cards and switch index cards with another group in the class. Students organize the index cards in the correct order and place in the correct positions on the roller coaster. Students must explain and defend the reasoning for the order they picked.

29 Light bulb or Heat bulb? Inquiry through Energy Transformations in a Light bulb Teacher Pages 1. Review the energy transformations in a light bulb: 2. Ask students, to think about if all light bulb transformations are the same? When energy transfers to a large system, it may be difficult to measure the effects of the added energy. Dissipated energy (energy that is transformed into thermal energy and released into the surroundings) is difficult or impossible to recapture. Some systems, such as certain light bulbs, dissipate less energy than others, leaving more energy to use. It is suggested to facilitate as students develop their own investigation to test and compare the amount of energy (thermal) dissipated in various bulbs, and to explain how the energy transformation takes place in order to understand the differences in energy input/output. Example investigation: The following lesson has been adapted from the Ohio Energy Project e3 Smart Curriculum Light Bulb or Heat Bulb lesson. PURPOSE: to introduce students to how lighting affects their energy usage and how changing the type of light bulb used can dramatically change that. Perhaps NO measure is more effective, than changing a bulb, in terms of easy energy conservation action. The energy savings are dramatic. This experiment allows students to draw conclusions comparing the two types of light bulbs: compact fluorescent light bulbs (CFLs) and incandescent light bulbs (ILs). MATERIALS NEEDED: Lamp bases or clamp lights Timers Calculators Thermometers Light bulb packaging with prices (or copies of sample packaging WS) Incandescent light bulbs (IL) Compact fluorescent light bulb(cfl)

30 FOR CONVENIENCE, THIS EXPERIMENT IS BROKEN INTO TWO PARTS. For Part I, students compare the structure of each bulb, and the heat generated by each bulb measured by the change in temperature. For Part II, students compare the costs of purchasing and operating each type of bulb. PART I PROCEDURE: 1) Begin the unit by showing the 2 types of light bulbs: compact fluorescent light bulbs (CFLs) and incandescent light bulbs (ILs). Ask students which type they use the most at home. Ask students if they use CFLs in their home. Ask students which type of bulb they think is better. Ask students what type of lighting is used in school (fluorescent). Explain that a CFL uses the same basic technology as a fluorescent light bulb at school. Tell students that they are doing a scientific experiment comparing CFLs to ILs. Tell students this is important in energy use because between 10-20% of their electricity bill pays for lighting in their home. 2) Ask students to observe the structure of each type of bulb in the lamp bases. Ask students to sketch each bulb and put observations about the structure of each bulb in the data table. 3) Demonstrate how to read the thermometer. If possible, groups can run both lamps at once. For safest data collection, mount the thermometer on a stand or lay the thermometer on a table next to the lamp bases, so the students do not have to hold the thermometers. The thermometers could even be taped on a box to the correct height above the lamp bases or below the clamp lights. Remind students to keep thermometers the same distance from each bulb. Remind students to take the temperature before they turn on the lights. Have the timer begin timing after the starting temperature is determined and recorded. Be sure the lamp bases are not next to each other. BE SURE NOT TO TOUCH THE BULBS ONCE THE LIGHT IS ON - ILs GET HOT! 4) Once students have completed the graph, discuss results of the first part of the lab. Discuss the different appearance and feel of each bulb. Remind students that a compact fluorescent light bulb is a rolled up fluorescent light tube. Discuss the change in temperature for the 2 bulbs. Review the results on their graphs. Discuss why the incandescent bulb gets so much hotter. Explain how the filament in the bulb actually gets so hot it emits light and glows. Explain that compact fluorescent bulbs do not have a filament. Students may have noticed this while observing the bulbs. CFLs are actually a tube of gas. When electricity flows through the gas from an electronic or magnetic ballast, the gas emits ultraviolet light. That ultraviolet light (UV) strikes a painted white phosphor coating on the inside of the tube. Phosphor is a substance that can emit visible light when it is struck by UV light. So the coating glows. Adapted from Ohio Energy Project s e3 Smart Curriculum Light Bulb or Heat Bulb lesson

31 PART II PROCEDURE: 1) Explain that in Part II of the lab, they will compare the costs of purchasing and operating the two types of bulbs. 2) Review the following terms. They will be used in Part II of the lab. Lumens - a measure of the amount of light falling on an object at a given distance Watts - units of power, the rate at which a bulb or appliance uses energy. Kilowatt watts. (It is more useful when talking about electricity use than a single watt because we use so many thousands of watts.) Kilowatt-hour - the unit in which we buy electricity. It is a unit for energy. It is equal to 1000 watts used for one hour. Kilowatt-hours are calculated by kilowatts X hours used. Life Expectancy - the average time a bulb has been tested and is expected to operate in hours under normal use. 3) Background info: The average cost of 1 kwh is $0.11 in Ohio. 4) If possible, distribute real light bulb packaging. 5) Help students work through the calculations. Two versions are available. Pick which version is most appropriate for your students. A key for each table is provided with sample data from the sample packaging. The first version, LET S COMPARE! 12,000 Hours of Light is geared toward lower grades. The second version CALCULATING THE COST OF 12,000 HOURS OF LIGHT is geared toward upper grades. 6) Review the data, calculations, and questions. Students will probably be amazed by their findings. Discuss the merits of each bulb. Ask students which bulb they think is better now. Ask students why they think some people are resistant to trying CFLs. (Want to generate some more drama? Share some of THE AMAZING LIGHTBULB FACTS with your students. 7) Instruct students to transfer the appropriate data to the CFL vs IL: The Big Picture graphic. They will take this home to share with their parents. 8) Discuss variables that were controlled (kept the same) in this experiment (e.g. distance, thermometers, bases, time interval, location, lumens). Discuss variables that were changed (e.g. bulb type). Discuss any variables that were uncontrolled (e.g. different thermometer readers). Discuss how the experiment might be changed for improvement. 9) Give each student an ENERGY SAVERS booklet to take home. Review the pages they will read with their parents on the LIGHT BULB OR HEAT BULB AT HOME home activity (pages 20-21). Online version may be found at: Adapted from Ohio Energy Project s e3 Smart Curriculum Light Bulb or Heat Bulb lesson

32 Name Date Period Light Bulb or Heat Bulb? PART I: Purpose: to compare an incandescent light bulb to a compact fluorescent light bulb Materials: 1 incandescent light bulb (IL) 2 thermometers 1 compact fluorescent light bulb (CFL) light bulb packaging for IL and CFL 2 lamp bases or clamp lights 1 calculator Hypothesis: Which light bulb do you think will give off the most heat? Which light bulb do you think will use more electricity? Procedure: 1) Observe each light bulb. Sketch and record their physical characteristics. Be very careful with the bulbs. Do not shake the bulbs. Observations (Physical Characteristics): Compact Fluorescent Light Bulb (CFL) Incandescent Light Bulb (IL)

33 2) Put a compact fluorescent light bulb (CFL) in the lamp base or clamp light. Hold or place the thermometer 5-10 cm from the bulb and take the temperature. Take the temperature every minute for 10 minutes and record it in the data table. 3) Put an incandescent light bulb (IL) in the lamp base. Hold or place the thermometer 5-10 cm from the bulb and take the temperature. (Make sure the thermometer is at the same distance from the bulb as before.) Take the temperature every minute for 10 minutes and record it in the data table. BE CAREFUL NOT TO TOUCH THE BULB. 4) Calculate the change in temperature for each bulb. Data Table: Time (min) Change in Temperature Temperature of Compact Fluorescent (CFL) Bulb ( C) Temperature of Incandescent Light (IL) Bulb ( C) 5) Graph the results of your temperature experiment. Use one color for the compact fluorescent light bulb and one color for the incandescent light bulb. Make a key showing which bulb each color represents. Label each axis and give the graph a title. Adapted from Ohio Energy Project s e3 Smart Curriculum Light Bulb or Heat Bulb lesson

34 Name Date Period Graph: Color Key: Time (minutes) CFL IL Adapted from Ohio Energy Project s e3 Smart Curriculum Light Bulb or Heat Bulb lesson

35 Sample Data Teacher Key Adapted from Ohio Energy Project s e3 Smart Curriculum Light Bulb or Heat Bulb lesson Data Table: Time (min) Temperature of Compact Fluorescent (CFL) Bulb ( C) Temperature of Incandescent Light (IL) Bulb ( C) Change in Temperature Graph:

36 Name Date Period Questions: 1) Do your results support your hypothesis? Explain. 2) What characteristics do the light bulbs have in common? 3) How do the light bulbs differ? 4) Which light bulb is coolest? 5) Which bulb is truly a heat bulb, not a light bulb? Explain your answer. 6) How does this experiment relate to energy transformations?

37 Questions: - TEACHER KEY 1) Do your results support your hypothesis? Explain. Answers will Vary 2) What characteristics do the light bulbs have in common? Size is fairly similar, same electrical input, both made out of glass with a similar metal base, 3) How do the light bulbs differ? Structure is different IL is one whole bulb and the CFL is a coil of glass tubing; the IL has a filament that heats up surrounded by Argon gas and the CFL is filled with gas and mercury vapor. 4) Which light bulb is coolest? CFL 5) Which bulb is truly a heat bulb, not a light bulb? Explain your answer. The CFL emits a tremendous of amount of heat in addition to light. 6) How does this experiment relate to energy transformations? Electrical energy enters the light bulb, which is then transformed into thermal energy and light energy.

38 Name Date Period Part II. LET S COMPARE! 12,000 Hours of Light Purpose: to compare the costs or purchasing and operating IL and CFL bulbs Materials: IL and CFL packaging, calculator Hypothesis: For each statement circle CFL(Compact Fluorescent Light) or IL(Incandescent Light) 1. Which light bulb do you think will cost the most to purchase? CFL IL 2. Which light bulb do you think will cost the most to operate? CFL IL 3. Which light bulb do you think will be most efficient? CFL IL Vocabulary: Lumens - A measure of the amount of light falling on an object at a given distance. Watts Units of power, the rate at which a bulb or appliance uses energy. Kilowatt 1000 watts. Kilowatt-hour The unit in which we buy electricity. It is a unit of energy. It is equal to 1000 watts used for one hour. Life Expectancy The average time a bulb has been tested and is expected to operate in hours under normal use. Background: The average cost of 1 kilowatt-hour is $0.11. Procedure: 1) Use the Let s Compare worksheet. Look at the packaging of the light bulbs. Use the packaging or the sample packaging sheet to record the Light Output in lumens, the Power Used in watts, the Life Expectancy in hours, and the Cost per Bulb 2) Do the calculations comparing the cost of light bulbs and record the data in your table. 3) For the LET S COMPARE! 12,000 Hours of Light data sheet, use the facts on the packaging and the current average cost per kilowatt-hour to calculate the numbers to complete the data. 4) Transfer your numbers to the CFL vs IL: The Big Picture sheet. Calculate the life cycle savings. Adapted from Ohio Energy Project s e3 Smart Curriculum Light Bulb or Heat Bulb lesson

39 Sample Packaging CFL: Sample cost of CFL = $2.00/bulb IL: Sample cost of IL = $0.20/bulb Adapted from Ohio Energy Project s e3 Smart Curriculum Light Bulb or Heat Bulb lesson

40 Name Date Period LET S COMPARE! 12,000 Hours of Light SAVINGS=$ -$ =$ Adapted from Ohio Energy Project s e3 Smart Curriculum Light Bulb or Heat Bulb lesson

41 Name Date Period LET S COMPARE! 12,000 Hours of Light Adapted from Ohio Energy Project s e3 Smart Curriculum Light Bulb or Heat Bulb lesson