Teacher Name: John Borud District: Montello Class / Subject / Grade:

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1 Teacher Name: John Borud District: Montello Class / Subject / Grade: Physics Unit Topic: Investigating Magnetic fields Allocation of Time: 6 days Using Technology with Classroom Instruction That Works skills to be taught and level of proficiency: (double-click in box to check it): Identifying Similarities and Differences Non-Linguistic Representation Summarizing and Note-Taking Setting Objectives and Providing Feedback Questions, Cues, and Advance Organizers List Technology Tools used to support the teaching of the above selected Using Technology with Classroom Instruction that Works strategies and describe how it will support the strategies: Vernier magnetic field sensor and Logger Pro software, Digital video camera ITLS Standards with grade-level benchmarks OR NETS for Students and level of proficiency: (at least two) (Example: Standard A.8.5: Students will use a graphic organizer program to create a Venn Diagram to compare to stories. Proficiency: 100% accuracy.) A.12.5 Use media and technology to create and present information. Proficiency: 100% accuracy B.12.7 Communicate the results of research and inquiry in an appropriate format. Proficiency: 100% accuracy D.12.1 Participate productively in workgroups or other collaborative learning environments.

2 Curriculum Content and/or Performance Standards: (at least two) A.12.6 Identify and, using evidence learned or discovered, replace inaccurate personal models and explanations of science-related events. C.12.2 When studying science content, ask questions suggested by observations of phenomena, build hypotheses that might answer some of these questions, design possible investigations, and describe results that might emerge from such investigations. C.12.3 Evaluate the data collected during an investigation, critique the data-collection procedures and results, and suggest ways to make any needed improvements. Learning Objectives: What students will learn To experimentally learn about magnetic fields and determine the relationship between distance and field strength of a magnet. How to use digital probes and analyze the information collected. How to use a digital video camera to make a movie demonstrating how to use the digital magnetic probe. Step-by-step Unit Plan and Timeline: Activities that will be used to develop understandings (Please provide enough details that another teacher could pick-up and teach the unit.) Day 1: Introduce and lecture on magnetism and introduce tomorrow s lab on magnetic fields. Day 2: The students are working in groups of two and will conduct a fairly standard lab (Magnet Handout 1) to investigate the magnetic field around a magnet using a small compass and then to observe it by sprinkling iron filings on Plexiglas over various magnets. Some parts of the lab are open-ended questions that they are to answer and support with experimental observations. Day 3: Introduce the Logger Pro software and demonstrate how to use the magnetic field sensor. (Magnet Handout 2) The final part of the lab is to use the Vernier magnetic field sensor probe and the Logger Pro software to map the magnet field strength versus distance and then use the analyze functions to investigate what type of curve best fits the data. Each group will print their data collected and the graph and analysis of it. The small group work with the magnet field sensor probe allows the students to see the magnet field strength go down. Trying to understand what they observe allows students to use knowledge and comprehension from Bloom s taxonomy along with some application and analysis. (See Lab Results Handout) Day 4: Give class instructions on how to use the digital cameras (Should be a quick review) The rest of class is spent working in groups finishing their lab if they need extra time and to make a short movie demonstrating how to use the digital magnetic probe or sharing what they learned about the magnetic field of a magnet using demonstrations. Day 5: Review the magnetism unit by discussing the lab results and answering any student questions.

3 Day 6: Give class time to complete online assessment and unit exam. Assessments**: Formative and summative assessments that will measure understanding of each learning objective and/or activity ** Include descriptions or attach copies of all assessment instruments. Unit assessment using Survey Monkey. Teacher observation of progress during lab/project. (See Lab Results Handout) Rubric for grading lab/movie.(see Lab Rubric and VideoLab Rubric ) Unit Exam Resources & Technology Tools**: Resources that will be used to develop understanding ** List resources and attach copies of any handouts created for the unit. Digital video camera Vernier magnetic field sensor Logger Pro software Differentiation Strategies: Strategies to make sure that all students can be successful Allow students to watch a demonstration of using the technology. Provide both written and oral directions for using technology. Monitor the lab and assist students who are having difficulty. Handout 1

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5 Handout 2 Lab from Vernier Physics with Computers With changes made by John Borud The Magnetic Field of a Permanent Magnet A bar magnet has two poles: north and south. We call the such a magnet a dipole since it has two poles, commonly labeled North and South. Breaking a magnet in two does not produce two isolated poles; each fragment still has two poles. Similarly, two magnets together still exhibit only two poles. Since to our knowledge there are no magnetic monopoles, the dipole is the simplest possible magnetic field source. The dipole field is not limited to bar magnets, for an electrical current flowing in a loop also creates this common magnetic field pattern. The magnetic field B axis (measured in tesla) of an ideal dipole measured along its axis is where µ 0 is the permeability constant (4π 10 7 T m/a), d is the distance from the center of the dipole in meters and µ is the magnetic moment. The magnetic moment µ measures the strength of a magnet, much like electrical charge measures the strength of a electric field source. Note that the distance dependence of this function is an inverse-cube function, which is different from the inverse-square relationship you may have studied for other situations. In this lab, you will examine how the magnetic of a small, powerful magnet varies with distance, measured along the axis of the magnet. A Magnetic Field Sensor will be used to measure the magnitude of the field. Simple laboratory magnets are approximately dipoles, although magnets of complex shapes will exhibit more complex fields. By comparing your field data to the field of an ideal dipole you can see if your magnet is very nearly a dipole in its behavior. If it is nearly a dipole, you can also measure its magnetic moment. OBJECTIVES Use a Magnetic Field Sensor to measure the field of a small magnet. Compare the distance dependence of the magnetic field to the magnetic dipole model.

6 Measure the magnetic moment of a magnet. MATERIALS Power Macintosh or Windows PC masking tape LabPro or Universal Lab Interface strong disk magnets (2) Logger Pro tape measure or meter stick Vernier Magnetic Field Sensor index card PRELIMINARY QUESTION Figure 1 1. Place one magnet on a table and hold the other in your hand, well above the first. From directly above, slowly lower the upper magnet toward the first. Watch for the moment when the lower magnet jumps up to meet the upper. Separate the magnets and try again. From the sudden jump of the lower magnet, what can you conclude about the way the magnetic force between the magnets varies with distance? PROCEDURE 1. Tape the measuring tape or meter stick to the table, and tape the Magnetic Field Sensor to a convenient location. The clear plastic rod should be perpendicular to the stick, with the white spot inside the rod facing along the meter stick in the direction of increasing distance. Carefully measure the location of the sensor on the meter stick. This will be your origin for all distance measurements.

7 2. As a convenient way to measure to the center of the magnet, and to ease handling of the small magnets, allow the two magnets to attract one another through the card, about 0.5 cm from either edge near the corner. The magnets should stay in place on the card. The card itself will serve to mark the center of the magnet pair. 3. Connect the Vernier Magnetic Field Sensor to Channel 1 of the LabPro or Universal Lab Interface. Set the switch on the sensor to Low. 4. Open the file in the Experiment 31(Magnetic field of a Permanent Magnet) folder of Physics with Computers. A graph will appear on the screen. The vertical axis of the graph has magnetic field scaled from 0 to 6 mt. The horizontal axis has distance scaled from 0 to 0.10 m. The Meter window will display the magnetic field in mt. 5. We will first zero the sensor when the magnets are far away from the sensor in order to remove the effect of the Earth s magnetic field and any local magnetism. The sensor will be zeroed only for this location, so instead of moving the sensor in later steps, you will move the magnets. a. Move the magnets far away from the sensor. b. When the reading in the meter window is stable, click. 6. Now you are ready to collect magnetic field data as a function of distance. a. Click to begin data collection. b. Place the card with the magnets against the meter stick, 3.0 cm from the Magnetic Field Sensor, so the card is perpendicular to the meter stick. Measure from the card to the center of the Magnetic Field Sensor. c. The current magnetic field measurement is shown in the meter window. If necessary, reverse the magnets so the reading is positive, and reposition the card 2.0 cm from the sensor. If the reading is more than 6 mt, then increase the distance until the reading is below 6 mt. d. Carefully measure the distance of the card to the sensor. e. Click to record the magnetic field. f. To make later calculations easier, on the computer enter the distance in meters, e.g., 2 cm is 0.02 m. Press ENTER to complete the entry. 7. For the next ten points, a. Keeping the Magnetic Field Sensor stationary, increase the distance to the magnet by 0.5 cm. b. Click to record the magnetic field. c. Enter the distance in meters on the computer. d. After the last point, click to end data collection. The graph you see is the magnetic field vs. the distance from the magnet. The field should drop off rapidly. DATA TABLE Model parameter A

8 µ (A m 2 ) Magnetic moment ANALYSIS 1. To compare your data to the inverse-cube model you can plot the equation y = A/x 3 along with your data. To plot your data and the inverse-cube model on the graph at the same time a. Select Curve Fit from the Analyze menu. A new dialog box will open. b. Select Variable Power from the General Equation list. c. Enter 2 in the Degree/Exponent field. This setting adjusts the fitted function to an inverse-square relationship. d. Click to see the fitted function. e. Repeat steps c and d with 3, and 4. Choose the best fitting exponent and proceed to step f f. Click to return to the main graph window. g. Record the numeric value of A in your Data Table. 2. How well does the inverse-cube model fit your experimental data? From the comparison, does your magnet show the magnetic field pattern of a dipole? 3. The computer adjusted the parameter A so the equation s curve comes as close as possible to your data points. Relating the parameter A to the field expression for a magnetic dipole, we see that A = (µ 0 2 µ 10 3 ) / (4π). The factor of 10 3 is present because the magnetic field was measured in mt rather than T. Use your value of A to determine the magnetic moment µ of your magnet, if the inverse-cube model fits your experimental data. EXTENSIONS 1. Find other magnets such as refrigerator magnets, horseshoe magnets, and disk magnets, and see if they also show the magnetic field of a dipole. 2. Measure the dipole moment of just one neodymium magnet, or four stuck together. Is the dipole moment additive when you use two or more magnets attracted together? 3. Show that the units of the magnetic moment are A m 2 (ampere meter 2 ). 4. The units of µ may suggest a relationship of a magnetic moment to an electrical current. In fact, a current flowing in a closed loop

9 is a magnetic dipole. A current I flowing around a loop of area πr 2 has a magnetic moment µ = I πr 2. If a single current loop had the same radius as your permanent magnet, what current would be required to create the same magnetic field? (You will be surprised.) Are there currents flowing in loops in the permanent magnet? Lab Results Mapping a magnetic field Using a digital magnetic field probe Graph of Data Collected Linear Test Fit to Data Not a Very Good Fit!

10 Lab Report : Magnetic Fields Teacher Name: John Borud Student Name: s better CATEGORY Components of the report All required elements are present and additional elements that add to the report (e.g., thoughtful comments, graphics) have been added. All required elements are present. One required element is missing, but additional elements that add to the report (e.g., thoughtful comments, graphics) have been added. Several required elements are missing. Drawings/Diagrams Participation Cubic Test Fit to Data Wow, Almost a perfect fit! Clear, accurate diagrams are included and make the experiment easier to understand. Diagrams are labeled neatly and accurately. Used time well in lab and focused attention on the experiment. Diagrams are included and are labeled neatly and accurately. Used time pretty well. Stayed focused on the experiment most of the time. Diagrams are included and are labeled. Did the lab but did not appear very interested. Focus was lost on several occasions. Needed diagrams are missing OR are missing important labels. Participation was minimal OR student was hostile about participating. Analysis The relationship between the variables is discussed and trends/patterns logically analyzed. Predictions are made about what might happen if part of the lab were The relationship between the variables is discussed and trends/patterns logically analyzed. The relationship between the variables is discussed but no patterns, trends or predictions are made based on the data. The relationship between the variables is not discussed.

11 changed or how the experimental design could be changed. Data Professional looking and accurate representation of the data in tables and/or graphs. Graphs and tables are labeled and titled. Accurate representation of the data in tables and/or graphs. Graphs and tables are labeled and titled. Accurate representation of the data in written form, but no graphs or tables are presented. Data are not shown OR are inaccurate. Video- Preproduction : Digital Probe "How to" Video Teacher Name: John Borud Student Name: CATEGORY Score Concept Team has a clear picture of what they are trying to achieve. Each member can describe what they are trying to do. Team has a fairly clear picture of what they are trying to achieve. Team has brainstormed their concept, but no clear focus has emerged for the team. Team has spent little effort on brainstorming and refining a concept. Team members are unclear on the goals. Script Script is complete and it is clear what each actor will say and do. Entries and exits are scripted as are important movements. Script is mostly complete. It is clear what each actor will say and do. Script is shows planning. Script has a few major flaws. It is not always clear what the actors are to say and do. Script shows an attempt at planning, but seems incomplete. There is no script. Actors are expected to invent what they say and do as they go along.

12 Equipment Preparation All necesary equipment/supplies are located in advance. All equipment (sound, light, video) is checked before the shoot. All necesary equipment/supplies are located in advance. On the day of the shoot, most necesary equipment/supplies are located. Many needed supplies/equipment are missing OR were not checked before the shoot. Teamwork All students contribute to the discussion and all are listened to respectfully. All team members contribute a fair share of the work. Most students contribute to the discussion and are listened to respectfully. Many team members contribute a fair share of the work. Most students contribute to the discussion and are listened to respectfully. A few team members do not contribute a fair share of the work. Few students contribute to the discussion. Some team members do not contribute a fair share of the work. Quality of Final Project Information was clear and concise. Explanation was thorough enough for a fellow Physics student to complete the lab with little or no help. Information was fairly clear and concise. Explanation was thorough enough for a fellow Physics student to complete the lab with only a few extra instructions. Information was somewhat confusing. Explanation was fairly thorough, although some steps were missing. It would be difficult for a fellow Physics student to complete the lab without a fair amount of explanation. Project was completed, but difficult to follow and several steps were missing. It would be very difficult for a fellow Physics student to complete the lab using this video.