* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download lesson content goals guiding questions
Survey
Document related concepts
Transcript
Magnetism and Electricity Lesson 5 4th Grade INTENDED CURRICULUM BIG IDEA: (display in class during the lesson) Electricity and magnetism are related effects that have many useful applications such as conversion into heat, light, motion, and magnetic effects Establish working word wall throughout the lesson. Magnetism and electricity investigation 4.1 and a section of 1.2 LESSON CONTENT GOALS GUIDING QUESTIONS (display in class after prediction) 1) An electric current produces a magnetic field and can be changed into heat, light, and motion. 1) How can we detect if an electric current is present in a circuit that has no receivers? 2) An iron bar is magnetized when a currentcarrying wire is wrapped around it several times, this is called an electromagnet. 2) How can an iron nail become magnetized with an electric current? 3) The number of coils (turns) in a currentcarrying wire affects the strength of the magnetic field it produces. 4) Electromagnets can be used in motors, generators, earphones and doorbells. 3) How does the number of coils in a currentcarrying wire produce a stronger magnetic field in a simple series circuit? 4) What use is an electromagnet known to have in our homes? TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 1 IMPLEMENTED TEACHER’S NOTES: CURRICULUM Students will investigate the relationship between electricity and magnetism. This lesson will take at least 7 days to teach. ( 40 - 45 min.) Advanced Preparation for the Lesson Use 8 new D-cell batteries for this lesson. 18 copies of Oersted’s investigation to read along. Read from Science stories pages 24-32 Materials needed for a group of 4 students Part I 2 copies of Oersted’s investigation 1 compass 1 D-cell battery 2 long and one short insulated wires 1 Circuit base 1 switch Part II 1 electromagnet wire 150 cm, 24-gauge 1 rivet 1 D-cell battery and bulb holder 1 Circuit base 1 switch 50 small washers, 1 cm diameter 1 plastic cup to store washers Reading Part III 4 Science story books 1 Opened motor 1 Working motor with flags( to demonstrate how they work only) TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 2 Brief Lesson Review Read engaging scenario, check for clues Discuss what needs to be investigated or designed for this investigation. Read and discuss Oersted’s investigation as a class. Introduce circuit base to replicate Oersted’s experiment. Observe demonstration on making a temporary magnet through induction. Revisit focus question to discuss prediction. Record prediction statement and drawing of prediction in notebooks. Organize 4 set ups for the number of winds the rivet will be tested in class. Discuss and design a chart to record the number of washers picked up by rivet. Record chart in notebooks. Listen to explanation on how to find averages. Follow directions on how to test the electromagnet. Group retests the design that attracted the most washers and average results. Read pages 25-27, “How electromagnetism stopped a war” and discuss. Making Meaning conference: analyze data obtained and practice doing claims and evidence. Claims and evidence: students write a claim for each of the guiding questions. Conclusion: Revisit prediction and write a statement of support or non support. Reflection: Write a: What would happen if ….question or I wonder if…. TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 3 DAY ONE PART I ENGAGING SCENARIO I spoke to the park ranger and reported your conclusions on hanging bar magnet to use it as a compass because both point to Earth’s magnetic pole. I told him about your investigations with parallel and series circuits and he gave me another challenge for you. He said that electricity and magnetism are somehow related. He said that with a simple series circuit with no receivers we can make an iron metal a magnet that could attract about 25 washers at the same time!!! He challenged us to investigate if this is possible and gave me some notes on this to read to you. What do we have to investigate here? FOCUS QUESTION (display, discuss by groups, record in notebooks) Guide students to identify the problem and identify it as a question. Teacher says: “What did the park ranger say about electricity and magnetism? Electricity and magnetism are related What did he say about a simple series circuit? Simple series circuit with no receivers made a magnet out of a metal item. How many metal washer did the metal item attract? The metal item attracted 25 washers at the same time. What does he want us to do? To investigate how electricity made a metal object a magnet that attracted 25 washers. Have students discuss what they need to investigate. Remind them that this will be the focus question in this investigation and they have to record it in their notebooks. Walk around the classroom and listen to their ideas. Check their notebooks and provide feedback .Select problems that relate to the investigation and have the share with the class. If students are having difficulty, sharing FQ from the other groups will help them decide. They may use one of the samples shared and record it in their notebooks below their own as CLASS FOCUS QUESTION. Suggested focus question How can we make a metal item a magnet and pick up 25 washers, using a simple series circuit with no receivers? Check and provide feedback TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 4 Teacher’s notes: Word Wall Switch: device that opens and closes a circuit A brief reading on Hans Christian Oersted is provided at the end of the lesson for you to make copies. (For additional information check http://www-istp.gsfc.nasa.gov/Education/Imagnet.html or http://www.micro.magnet.fsu.edu/electromag/java/comapss/index.html ) Read it along with students either by making copies or a transparency on the overhead. Discuss the reading with students. Teacher says: “What did he accidentally discover?” A wire with electricity flowing through it converts it into a magnet. “How did he test the compass?” First placing it above the wire and then beneath the wire and in the N-S direction. “What new component did he add to the series circuit?” Switch “What do you think is the purpose of a switch in a circuit? To turn the current on and off. I have placed a circuit base at your table that has a switch so you can replicate Mr.Oersted’s experiment and use it to build the circuit. (do not give them the battery)Take a look and discuss how the switch works when connected to a circuit. Be prepared to share.” Possible explanation: When you lift up the arm the circuit is broken so electricity does not flow. When you lower the arm then the circuit is again connected and electricity will flow through the wire. Demonstrate this if necessary. IMPORTANT NOTE: The current should not be connected when students are not testing. The energy source will be drained too quickly if this is done. Inform students that they will have to be very cautious about connecting and disconnecting the circuit. The circuit should be on for no more than 10 seconds at a time. Teacher says: “I am going to give you 2 wires to connect to the switch on the circuit base first. Leave the switch open. Before I deliver the source and the compass I want to see the wires connected correctly. to the switch. As I see you ready, I want you to connect the wires to the battery holder before I give you the source.. Walk around checking they have connected the wires correctly to the switch and battery holder, the arm switch should be on the off position. Assist them if necessary. Teacher says: “Record in your notebooks the title for this: “Mr. Oersted’s experiment. As you replicate this experiment, add your observations and if you have questions write them down.” Observe that everyone has written the title in their notebooks. Orally check for TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 5 understanding by reviewing what they will be doing. Make sure the switch is connected only for 10 seconds. Provide them with the source and compass to they can replicate the experiment. Teacher’s Note: This replication should take no more than 3 minutes to test. Once the compass is in place the switch should be connected for 10 seconds only for student to observe. To avoid loosing energy from the sources, collect sources as soon as students finish their observations. Once students replicate this experiment have them share and discuss their observations. Assist them in concluding that a carryingcurrent wire becomes a temporary magnet by having them share what they observed. They will continue their investigation the next day. TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 6 DAY TWO: PART II PREDICTION (discuss in groups, record in notebooks) Demonstrate magnetic interactions: using the rivet. Teacher says: “Observe what I can do with this magnet.” Word Wall Rivet: nail, bolt Take a permanent magnet and pick up washers from one cup and move them to another cup. Teacher says: “This is called a permanent magnet because it cannot be turned off.” Word Wall Permanent: stays for ever Take the magnet and use it to pick up the rivet. “This is called a rivet, it is not a magnet, it is a metal attracted to a magnet.” Word Wall Induced: passed on Take the magnet with the rivet to pick up some washers. Magnetism is induced, passed on to the rivet. As long as the magnet is touching the rivet, the washers can be lifted by the rivet. “This rivet is attracting washers, because the magnet’s force is induced from the magnet. The rivet is not a permanent magnet it is only temporary as long as the magnet is touching it.” Demonstrate the rivet by itself not picking up washers Teacher says: “Let us go back to the focus question you wrote.” How can we make a metal item a magnet, using a simple series circuit with no receivers? “You already demonstrated that electricity can attract a magnet by using the compass. I demonstrated how to make a temporary magnet by induction (touch) without using electricity.” How can you investigate this problem using electricity? Discuss with your group how you can make the rivet a magnet using the simple series circuit you build before. By the way, the park ranger told me to give you this long wire to test the rivet through the current. He said he had wrapped it around the rivet but he did not tell me how many times or how. He said it ranged between 15 to 40 winds. So we will replace this long wire with one of the short wires you already have connected to the switch. He said you need to figure out how to wrap the wire and how many times we should wrap it in order to pick up the washers. Discuss with your group and record this as your prediction in your notebooks. Be ready to share your ideas.” Repeat this information if necessary and allow students time to discuss. Walk around to listen to some of their ideas. Guide students as needed and have them share their ideas when they are ready. If students are having difficulty, sharing their ideas will help them decide. Provide the prediction sentence starter only if necessary. Remember some could say at one end, others can say along the rivet, or at the middle. TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 7 . Example of a Prediction: (optional format) If we wrap the long wire around the rivet at one end X times, then it will pick up more than 25 washers because the wire when connected to the source will become a magnet and pass it to the rivet. “because” statement to justify their prediction. Check and provide feedback Teacher says: “Make a drawing next to your prediction of how you plan to do it. Indicate the number of times you will wrap the wire and where you will wrap it around the rivet. Students will draw how they will wrap the wire and where and how many times. Make a list on the board of the way the groups decided to test their predictions. Save this information for the next day. TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 8 DAY THREE DATA CHART (record in notebooks) Teacher’s Notes Review the number of winds the groups have suggested in their predictions. It has to be a number between 15 and 40 winds. Use the number of winds they suggest; making sure you have at least 4 different set ups to compare. The groups will report their results and record them in a class chart.(see sample chart at the end of this lesson) Students will have to test their electromagnet at least two times and average their results before reporting to the class chart. REVIEW with students how to average the results before you begin. Teacher says: “You will have to average the results of the two tests you do by adding the two numbers and then dividing them by 2. (Practice with imaginary numbers so students know how to do this on their own.). Data from each of the groups will be collected for students to average them. Teacher says: “We have the number of winds your group will make to test the rivet as it picks up washers. The ranger said his magnet was able to attract 25 washers at once. What are you going to record as you test the rivet?” Count and record the number of washers it can attract at once. “Design a chart to record the # of washers picked up by the rivet. Remember the number of winds your group will test as well as that of the other groups in the class. (post these on the board) Discuss with your group what your chart should look like.” Allow students to discuss their design. Walk around and listen to their ideas. If necessary offer suggestions on how they can do it. Have them share with the class. Suggest a data chart only if what they shared was not appropriate. Guide as much as you think it is necessary. (see suggested chart) Include another column in your chart to record the average from the two trials.” TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 9 Make sure they understand how to calculate an average before they start or do this with them. SUGGESTED data chart Number of Washers picked up by rivet with an electric current Winds around Washers picked AVERAGE rivet and where up Group I 30winds at center Trial I Trial II Group II 20winds at end Trial I Trial II Once all groups have a chart and know how to calculate the averages they will be ready to test their prediction the following day. TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 10 DAY FOUR Students will test their predictions. Review group previous assignments. Remind them that the switch will be turned on for 10 seconds at a time. Distribute the circuit base, with switch attached, one short wire and one long wire 50 small washers and the rivet. Do not distribute the source until they have finished setting up. PLACE THE FOLLOWING INSTRUCTIONS ON THE BOARD (use a transparency or make copies, see the template at the end of this lesson) 1) Open the switch 2) Place one end of the short wire on one of the clips of the switch and the other end to one clip of the source holder 3) Wrap the long wire around the rivet according to your group’s prediction. Connect one end of the long wire to the switch and the other end to the source holder clip. 4) Place 25 washers on one of the corner compartments of the circuit base. 5) You will have to show steps 1-4 to your teacher before the source is given to your group. 6) Place the source in place, and place the rivet over the washers 7) Connect the switch for 10 seconds to collect the washers. Then LIFT the washers with the rivet and place over the other empty compartment and turn the switch off. 8) Count the number of washers the rivet lifted and record it in your notebooks under trial I, then return them to the corner compartment again. 9) Repeat the steps 6-8 for the second trial. Read instructions with students and clarify questions where it is necessary. Make sure you do not provide sources until the groups have demonstrated that they know what they will do. Allow students to test once they are ready by distributing the source (battery). NOTE: This activity should take no more than 12 minutes to test. Students will share and record them in a class chart placed on the board or a transparency.( see template at the end of this lesson) Have students transfer the class results to their notebooks. Once the class results are recorded, they should calculate the average. Provide assistance with their math skills if necessary. Walk around to see that everyone has calculated the average for all the groups correctly and recorded them in their charts. TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 11 TEACHER’S NOTES: TRY THIS AFTER STUDENTS HAVE TESTED Allow students to test the group that lifted the most washers by checking the class averaged data. This can be done to verify the results collected by the groups. Make sure students know how many winds, where and how the wire was wrapped around the rivet. Each group should test once and report the results by placing them in another class chart (see sample chart II) and with teacher’s assistance will average the results. Save the data to discuss during the making meaning conference. SAMPLE CLASS DATA CHART II Retesting Use template at end of this lesson to make a transparency. _____Winds around rivet Group 1 Group 2 Washers picked up Group 3 Group 4 Group 5 Group 6 Group 7 Group 8 Average TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 12 DAY FIVE PART III: Uses of electromagnets. Word Wall Electromagnet: piece of iron that becomes a temporary magnet when wrapped around a current- carry wire. Students will read and discuss pages 25-32 of the science stories on “How electromagnetism stopped a war and Magnets and electricity in your life.” Teacher’s Notes: Emphasize the use of electromagnets in motors, generators, earphones and doorbells. Students need not know the details of how a motor or generator work, but understand the simple relationship of the magnet and electricity to make many things move. Use the working and opened motors for students to see the parts along with the reading. For additional resources on this topic look at the following websites: Explains uses of motors and how they work. www.howstuffworks.com/motor.htm The Exploratorium: Snacks about Magnetism: http://www.exploratorium.edu/snacks/iconmagnetism.html Molecular Expressions; Java tutorials developed to help students understand topics in electricity and magnetism: http://micro.magnet.fsu.edu/electromag/java/ TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 13 DAY SIX MAKING MEANING CONFERENCE (Teacher directed). 1) Share and display of class findings Use class charts to analyze results. Have students look at their own data charts to discuss the results. It is preferable that students pay attention and not take notes during this stage but contribute with their ideas. 2) Looking for patterns from the class findings. Teacher guides students to analyze the chart by making claims supported the evidence. “What does the data tell us about how a metal can be made into a magnet? Let’s analyze the differences between the washers picked up with a rivet with 15 turns and a rivet with 20 turns. What claim can we make about how and where of the winding of the wire makes an electromagnet the strongest? What claim can we make about the number of turns made around the wire and the total number of washers picked up? What does the data tell about the strength of a temporary magnet made with an electric current in a series circuit with one source? . Assist students to answer a claim using the results from their findings as evidence. CLAIMS EVIDENCE I claim that ……………. I know that……………. I claim this because ………….. I know this because………. 1.A temporary magnet can be turned on and off. 1. when we wrapped the current-carrying wire around the rivet it became a magnet, when we turned the current off, the rivet did not work as a magnet. 2. An iron object can be made into a magnet when in contact with a magnet. 2. when the rivet was in contact with the magnet it Picked up the washers and when it was not touching the magnet it did not pick up any washers. Teacher decides to list as many claims and evidence needed for students to understand the process. Once finished teacher says: “With our findings as evidence let’s REVISIT THE GUIDING QUESTIONS.” Read the guiding questions aloud. TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 14 DAY SEVEN CLAIMS AND EVIDENCE (record in notebook) Teacher says “You are now going to continue writing claims and evidence statements using the guiding questions. You must have at least 3 claims with evidence to support them. Revisit your charts and drawings to help you find evidence for your claims. Use the sentence structures to help you record them in your notebook.” I claim that an electric current is present in a circuit if………. I claim this because……….. I know that an iron nail can become magnetized by………… I know this because…………. Teacher will see students individually as they answer the guiding questions. Display examples of sentence structures if necessary Groups share and discuss their answers with the class Check and provide feedback CONCLUSION (record in notebooks) Students are then asked to revisit their prediction and write a sentence that states whether the evidence from their charts supported it or not. They are to explain why and provide clear explanations regarding how their evidence supported their prediction. Have the students write a concluding statement using a sentence starter such as: Today I learned….. Check and provide feedback REFLECTION (record in notebooks) Students will revisit the “Big Idea” and their results. They write a question they would like to learn more about the topic. Suggested sentence starters for this question What would happen if …………. I wonder if we……….. Students will be asked to share out their statements. Check and provide feedback . TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 15 ACHIEVED CURRICULUM PROFICENCY FEEDBACK: This guide is: To be posted on the board/butcher paper for students to know what is expected in their notebook to be an evaluation tool for teachers as students work in their notebooks. to be converted into questions as a student self assessment piece PROFICIENCY FEEDBACK GUIDE Focus Question: One question written clearly. . Related to the scenario. Prediction One statement Specifies the # of turns, where and how Uses “because” Data Oersted’s Observations & 1 chart Complete and accurate Labeled with titles Claims & Evidence 3 complete sentences showing understanding of guided questions. Conclusion Accurately shows if prediction was supported or not and explains why. Reflection: Writes an investigable question using What would happen if …related to the topic covered. TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 16 Reading material Hans Christian Oersted In 1820 a Danish school teacher accidentally found a relationship between electricity and magnetism. As Oersted absent-mindedly laid the current-carrying wire of an electric circuit beside a magnetic compass, he happened to notice the compass needle turning. He continued his investigation by placing the magnetic compass directly above a wire with an electric current flowing through it in an N-S direction to observe its movement. Then he took the compass and placed it beneath the wire and observed. He noticed that an electric current flowing through a wire caused the wire to behave like a magnet. The wires when connected to a source of energy create a magnetic field. Source Compass N - + Insulated wire Switch TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 17 Instructions for making an electromagnet. READ AND FOLLOW INSTRUCTIONS 1) Open the switch 2) Place one end of the short wire on one of the clips of the switch and the other end to one clip of the source holder 3) Wrap the long wire around the rivet according to your group’s prediction Connect one end of the long wire to the switch and the other end to the source holder clip. 4) Place 25 washers on one of the corner compartments of the circuit base. 5) You will have to show steps 1-4 to your teacher before the source is given to your group. 6) Place the source in place, and place the rivet over the washers 7) Connect the switch for 10 seconds to collect the washers. Then LIFT the washers with the rivet and place over the other empty compartment and turn the switch off. 8) Count the number of washers the rivet lifted and record it in your notebooks under trial I, then return them to the corner compartment again. 9)TESLA Repeat the steps 6-8 for the second trial. Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 18 CLASS RESULTS FOR TRIAL TESTING - CHART I #Winds and where # of Washers picked up GROUP TRIAL I TRIAL II GROUP TRIAL I TRIAL II GROUP TRIAL I TRIAL II GROUP TRIAL I TRIAL II GROUP TRIAL I TRIAL II GROUP TRIAL I TRIAL II GROUP TRIAL I TRIAL II GROUP TRIAL I TRIAL II AVERAGE TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 19 CLASS RESULTS FOR TRIAL RETESTING - CHART II # winds around rivet # of Washers picked up Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7 Group 8 Average TESLA Scaffolded Guided Inquiry , Grade 4 – Magnetism and Electricity DRAFT 8/1/07 20