Teaching Strategies
The concepts that lead to making a Generator follow Next Generation Science Standards provided below.
Performance Standards: 1) Motion, Stability and forces interactions, 2) Matter and its interactions, 3) Energy.
Practices: 1) Plan and Carry out investigations, 2) Developing and using Models, 3) Asking Questions a Defining Problems, 4) Constructing Explanations and Designing Solutions, 5) Analyzing and Interpreting Data.
Disciplinary Core Standards: 1) Forces in Motion, 2) Types of Interactions, 3) Definitions of Energy, 4) Relationship between energy and force, 5) Structure and Properties of Matter, 6) Conservation of Energy and Energy Transfer, 6) Developing Possible Solutions, 7) Wave Properties, 8) Electromagnetic Radiation.
Cross Cutting Concepts: 1) Energy and Matter, 2) Cause and Effect, 3) Patterns, 4) Scale, Proportion and Quantity, 5) Systems and system models, 6) Structure and Function.
The teaching strategies in this unit combine individual learning, collaborative learning, verbalization and hands on learning.
Vocabulary
The concepts for this work involve new vocabulary and knowledge of new concepts. The units for electricity and energy need to be understood clearly. I would like to use a website on the labtops called Kahoot! to practice vocabulary. Kahoot! is a game where the students have a certain amount of time, 10 sec or 20 sec, to answer a question. Each person gets points based on having the correct answer as well as having streaks of answers.
Collaborative Learning
One of the keys to teaching this unit is to create the hands-on activities and increase the difficulty of the activities to master the material as well as troubleshoot student challenges.
Verbal Communication
Each day the students will do a “Bell Ringer.” The Bell Ringer will have a concept question. The students will discuss the concept question. Before the students open the bell ringer, a student at each table will be designated to share out the discussion held at the table. After having 2 minutes to discuss the question, the assigned students will share the discussion.
Project Lead the Way
This is a Unit in Project Lead the Way (PLTW), which also lays out standards.
Activities
Activity 1. Magnetic Fields. Perform a demonstration in front of class using an ELMO type projector of the Magnetic Field given by a rectangular magnet. Place a pile of papers that hold the magnet in place. Place a sheet of paper above the magnet and below the lamp of the projector. Pour the iron filings around the magnet. Observe the magnetic field. The students are to draw the picture of the magnet and the magnetic field in their PLTW notebook. The students will write a paragraph, 5-6 sentences on what they observed and what it means. A worksheet will be provided in Google Classroom with questions on what they saw. The objective is for the students to explain a magnetic field. SAFETY: The iron filings are small, adhere to the skin and “fly” everywhere; thus, this is done as a demonstration.
Activity 2. Properties of Magnets. In pairs, hand out two circular magnets with a hole in the center, 2 circular magnets without a hole in the center, a piece of foam, access to the hot glue gun station, access to station with water, a piece of string, a sharpie and a compass. Put a map of Chicago on the wall. Ask the students to determine North in the classroom. First, have the students will determine the opposing poles by putting the magnets in the fold of a book. Put a dot using the sharpie on the same poles. Use the compass and the magnets to determine north. 1) Put a magnet on a string and determine north and see the side of the magnet facing north. 2) Cut a square piece of foam bigger than the magnet. Glue the edge of the circular magnet to the foam. Put the foam in the water. Identify and label on the foam N, S, E and W. The students will write in their PLTW notebook their observations and challenges. Did the North in the string and water experiment match the north on the compass? In the Bell Ringer on the next day, the students will discuss the next day if they were able to determine the direction north correctly, why and why not.
Activity 3. Fun with Magnets. From the front of the room the students will put in their bucket a battery, AA, a neodymium round magnet and a 10” length of copper. The students will wind the copper around the magnet. Leaving an inch at the top and a ¼ inch at the bottom. The negative pole of the battery will be placed on the neodymium magnet. The copper will be shaped to touch the magnet. The top of the copper wire will be shaped to touch the top of the battery. The wire will spin. This is a fun activity to have electricity and electromagnetism working together to have the wire spin.
Activity 4. Properties of Magnetic fields. Hand out 2 sheets of 12”Wx18”L aluminum foil. Put the sheets over each other and fold them in half to make it 6”W and 18”L. Ensure the aluminum foil is as flat as possible by using a book to press it down. Roll the Aluminum so it is larger than the magnet. Use a dowel rod or pencil to make the roll. Have one person watch the clock second hand. Determine how many seconds it takes the magnet to fall down through the aluminum roll. Repeat this 5 times and write the data in the PLTW notebook. Repeat the timing of the fall of the magnet the same distance, but without the aluminum foil. Write the values in the PLTW notebook. Calculate the average and % residual standard deviation for both experiments. The students will write their conclusion as to what role the aluminum foil had in the experiment. In the Bell Ringer for the next day, the students will do a share out of the role of the aluminum foil on the results. The students will make an Excel® file with a data table of their values, calculations, written conclusions and upload this to Google Classroom for grading.
Activity 5. Make a temporary magnet. Students will work in pairs. The student pair will pick up a nail, 5 paper clips and a magnet. Select three different sides of the magnet to test. For each side add paper clips and let them hang. How many paper clips can be places in series one below the other? A drawing will be made in their PLTW notebooks of the 3 locations on the magnet tested. A table will be made and the number of paper clips that hold in series will be documented. The students will answer the questions: are the paper clips magnets? When connected to a magnet, do the paper clips become magnets? What is a temporary Magnet? In the Bell Ringer for the next morning, there will be a question and a share out on what is a temporary magnet. The students will answer questions in Google Classroom regarding the experiment.
Activity 6. Make an electromagnet. Work in pairs. Collect in your bucket from the teacher 1 nail, 1 battery, a long piece of enamel copper wire, some electrical tape, 10 paper clips, 2 small pieces of flat copper tape and a small piece of sand paper. Make 400 tight windings around the nail. Leave 4 inches of winding at the beginning and at the end of the winding. Use the sand paper to remove half an inch of the red enamel exposing only the copper wire. Check that all the red enamel has been removed on the entire circular cylindrical surface. Put one piece of copper tape on the (+) side of the battery. Place one end of the copper wire on top of the copper tape. Sandwich the copper wire with another piece of copper tape and then insulate by putting electrical tape over the copper tape. Repeat for the (-) side of the battery. Use the nail to pick up as many paper clips as you can. Write in the shared excel document the number of paper clips picked up. See who in the class can pick up the most paper clips. Draw in your PLTW notebook your electromagnet. Write 5-6 sentences to explain the results. Remove the wires from the battery and return the materials. For the Bell Ringer for the next day, the question will be, how can the electromagnet be made stronger? The students will have a few minutes to discuss and then perform a share-out.
Activity 7. Prototype a windmill I [Figure 4(C) and 4(D)]. Students will work in pairs.
First, students will collect buckets to contain their parts from the front of the class and place inside 5 pre-cut 1” OD PVC pipe (1 piece is 1” long, another is 2” long, the next piece is the same length as the magnet and the last 2 pieces are ½” long), 4 square magnets, 1 nail, 2 x 5 inch or 1 x10 inch strip of thin iron metal, a wooden block, a plastic turbine, a small piece of sand paper, 2 LED lights and enamel coated copper wire. The students will have access to glue gun stations. On the PVC pipe, the same length 4 magnet will be glued to each of the side of the PVC pipe. The magnets will need to face the PVC pipe by alternate the North Pole facing the pipe, then the South Pole facing the pipe, the North Pole and then South Pole. The piece is called the rotor. It is critical that adjacent magnet poles oppose each other in facing the pipe. Out of the 1” pipe have the instructor cut out with the soldering iron a slot where the nail will rest. Out of the 2” pipe, have the instructor make a hole a little larger than the size of the nail using the drill press or the soldering iron. Take the nail and put tape around each side of the nail so it sets inside the PVC pipe with a snug fit. Figure out where the 2” long and 1” long PVC pieces fit on the board to that the nail rests on the 1” piece and the nail rotates inside the 2” PVC piece. Glue these pieces onto the block. The magnets glued to the PVC should not touch the bottom of the wood. Set the rotor with the nail going through the hole on one side and on top of the slot on the other side. Turn the nail and the magnets should turn easily. The next step is to make a stator. Take the 5” strip of iron and cut it in half with scissors. Make 5 equal lengths (1” each) of the iron strips. Tape them together tightly so they are touching each other. Repeat this for the other 5” strip of iron. Take the enamel covered copper and make 300 turns around the lead piece. Repeat for the other lead piece. Put one roll of tape around the copper windings to hold them together. Take each of the ½” long PVC pipe and identify where they are to be placed so the windings are close to the magnets, but not touching. Glue the PVC piping in place. Glue the winding to each of the PVC pipes. Glue the turbine to the front of the nail. To each side of the stator there are two wires. Use the sand paper to remove ½” of the enamel from the copper wire for both ends. Repeat for the other stator. For one side, wind the copper around the lead of the LED and repeat for the other LED lead. Repeat for the other side of the stator. Rotate the nail or the turbine and the lights will light. For the Bell Ringer for the next period, we will discuss the purpose of the magnets, their rotation and of the coiling of the wires. The current and voltage will be measured in a shared Google Sheets file to see who generated the most current.
Activity 8. Prototype a windmill II [Figure 5(3)]. Students will work in pairs.
From the front of the class, collect in your containers 2 CDs, 4 round magnets, 1 bobbin, a coil of enamel wire, 2 washers and a turning nub. On one CD draw with a sharpie to lines 90 degrees from each other, meeting in the center. Glue the CD to a piece of cardboard. Mount 4 circular magnets alternating the poles facing the CD. On the second CD, create 4 triangular or circular coils on the back (250 winds per coil). Make the coil of 200 winding around an empty toilet paper roll or around 6-8 pencils and all the windings are made out of one piece of insulated wire. Glue the coils to the 2nd CD and glue the opposite side of the CD to a rigid piece of cardboard. Glue two washers to each CD so that the coils and the magnets face each other. The hole in the washer should be just greater than the dowel rod that will go into the hole. The washer should be large enough to cover the hole of the CD, but small enough to not touch the coils nor the magnets. Glue a stack of washers so the coils and the magnets are close to each other, but do not touch. Glue the stack of washers to the bottom CD. Glue the dowel rod to the top CD (but not to the stack) and let the rest be a shaft to go almost to the bottom of the lower CD to minimize warping as the top CD turns. The top CD should turn freely. Attach with glue the blades to the top CD or make a mechanism that can fix the blades and then be glued to the top CD. Test the system for easy rotation of the top CD. It should rotate freely and without wobble.
Generator used in YNI Demonstration
As Wire, use enamel coated spool copper wire and write down the AWD number that tells the diameter of the copper. Collect 4 block magnets, a nail to be used as your shaft and a sheet of cardboard. Take the sheet of cardboard and cut out a piece that is about 22 cm x 8 cm. Fold the cardboard so there are 2 8x8 cm squares and 2 3x8 cm sides and glue 3rd side glue on to hold the cardboard together. (Scale according to the magnet size). Puncture with the nail a 1/8” hole and ensure nail is loose so it can rotate. Attach each of the 2 block magnets together and put on one side of the nail. Attach the other 2 block magnets on the other side of the nail so they repel each other. Put a spacer on each side of the nail in between the each pair of magnets to hold the 4 magnets together. Wrap the wire around the long side of the wire leaving the other two sides open. Wrap it 400 times with space between wrappings. Ensure that the magnets can rotate freely in the box. Make the blades. Select PVC pipe, plastic or cardboard and mark it so the instructor can cut it to make the blades. Cut a piece of 1/8” dowel rods and attach to each blade using a hot glue gun. Make a hub using a Styrofoam ball. Attach Dowel Rods to Hub. Attach Hub to Shaft. Test your wind turbine by blowing or bring a fan into the classroom. This procedure is not being used because gluing the magnets inside the cardboard housing is difficult to do without touching the hot glue. For reasons of safety, this method is not used.
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