ENERGY INVESTIGATION. Green Power Solar Schools Energy Education Program Sponsored by Santee Cooper

Transcription

1 ENERGY INVESTIGATION Team 2nd Edition Santee Cooper and your Electric Cooperative working together naturally Green Power Solar Schools Energy Education Program Sponsored by Santee Cooper

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3 Table of Contents Challenge I: Energy and Machines Activity Page Activity 1.1 Mechanical Energy 3 Activity 1.2 Mechanical Energy and Work 5 Activity 1.3 Inclined Planes 8 Activity 1.4 Levers 11 Activity 1.5 Pulleys 17 Activity 1.6 Machines and Tools 26 Activity 1.7 Design and Efficiency 29 Challenge II: Heat Energy Activity 2.1 Ice Cube Race 33 Activity 2.3 Conduction 34 Activity 2.4 Radiation 38 Activity 2.5 Solar Still 40 Activity 2.6 Convection 42 Activity 2.7 Save the Cube 45 1

4 Table of Contents Challenge III: Energy Transformation Activity Page Activity 3.1 Electric Circuits 46 Activity 3.2 Sources of Electric Energy 48 Activity 3.3 Electricity and Magnetism 52 Activity 3.4 Electric Motors 55 Activity 3.5 Generators 60 Activity 3.6 Power Plants 63 Challenge IV: Alternative Energy Activity 4.1 Conservation of Energy 69 Activity 4.2 Solar Cells 73 Activity 4.3 Solar Panel System 74 Activity 4.4 Solar Derby 78 Activity 4.5 Promoting Alternative Energy 81 2

5 Activity 1.1 Apply Potential and Kinetic Energy Student Procedure: In this activity you will be investigating how gravitation potential energy transforms into kinetic energy. Read all of the steps in the procedure and discuss them with your group before you begin. 1. Use books and the longest board to make a ramp. Put a book on the floor and lean the board on the book to make a ramp. 2. Place your K NEX car on the ramp near the top and observe the motion of the car. 3. Place a book about 2 meters from the end of the ramp to stop the car. 4. Add books to raise your ramp so that the car can be released from different heights. 5. Observe how the motion of the car changes as you add books and record your observations in your notebook. 6. Which height gave the car the most kinetic energy? How did you know? 7. At which point did the car have the most potential energy? What is your evidence? 8. At what point is gravitational potential energy zero? What is your evidence? 9. What do you think determines how much gravitational potential energy an object will have? 10. Draw three pictures on your whiteboard. o One picture of a car on a ramp with high potential energy. o One picture of a car on a ramp with low potential energy. o One picture of a car on a ramp with no potential energy. o Under the pictures explain why each picture represents the amount of potential energy that you claimed. Use evidence to from your activity in your explanation. 11. Take your car apart, inventory the pieces and return the materials to your teacher. 3

6 Activity 1.2 Explore Mechanical Energy and Work 4

7 Activity 1.2 Explore Mechanical Energy and Work Student Procedure: In this activity you will be conducting a controlled investigation. Read through the procedure before beginning this activity. The teacher will tell you when to begin. 1. Write the hypothesis that you are testing in your notebook. 2. Build your car according to the instructions. Remember that all cars should be built the same so that we can have a fair test and compare the results. 3. Tie three rubber bands together. Loop one rubber band around the orange connector and practice wrapping the rubber band around the back axel. Place the car on the floor and let the car go. 4. In this activity we will vary the number of times that we wind the rubber-band around the axel in order to determine the effect this has on the motion of the car. 5. We will run three trials for each different number of turns. (3 turns, 6 turns, 12 turns) Then we will measure how far each car travels. 6. We will measure the distance the car travels by first marking a starting line with masking tape. We will release the car and mark where it stops with another piece of masking tape. Write the number of turns for each trial on the piece of masking tape. If you made 3 turns write a 3 on the piece of masking tape. Leave the pieces on the floor until all of the trials are done. We will measure the distances after all of the trials have been run. 7. Write a brief description of the experiment in your notebook. 8. Insert the Data Table in your science notebook. 9. Make sure you have enough room to run your cars. When the teacher tells you to begin, conduct the investigation and record the results in your data table. 5

8 Activity 1.3 Explore 1 Measuring Force 6

9 Activity 1.3 Explore 1 Measuring Force Student Procedure: In this activity you will measure the force required to lift objects and build a car to prepare for the next activity. 1. Have the material getter pick up the materials. 2. Practice weighing different items in you materials box using the spring scale. Discuss the readings with your group and make sure everyone in the group can read the spring correctly. When you think you have mastered reading the scale, ask the teacher to come over to help make sure you are correct. 3. Use the pictures to construct your car so that it can hold ten washers. Check the pictures and model that the teacher made to make sure you build the car right. 4. Weigh the car and record the weight in your student notebook. 5. Answer the focus question in your notebook. 6. Leave the car and washer setup assembled for the next activity. 7

10 Student Sheet 1.3 A 8

11 Activity 1.3 Explore 2 Inclined Plane Student Procedure: In this activity you are going to investigate the effect that using a simple machine called an inclined plane has on the force it takes to lift the car with the washer weights. 1. Build a ramp using books stacked about 15 cm high and one of the boards. Measure the height of the book stack and record it in your chart. 2. Use the car with ten large washers (for weights) from the last activity. 3. Using the spring scale slowly lift the car at a constant speed (without using the ramp) straight up to the height at the top of the book stack. Record the force required in your chart. 4. We will investigate three different ramp lengths to see if the force needed to pull the car changes. Keep the height of the books the same for each trial. 5. There are three different-length ramps. Measure the length of each ramp and record the values in the chart. Predict which length of ramp will take the least force to pull an object up. Record this in your notebook. 6. Use the spring scale to measure the force needed to pull the car up each ramp slowly at a constant speed and record the measurements in the chart. Record in Your Notebook 7. What is the independent variable? 8. What is the dependent variable? 9. Make a graph of the results. Use student sheet 1.2 B and your DRY MIX sheet. 10. On your whiteboard draw a picture of the three ramps. Draw them in order beginning with the ramp that took the most force to pull the car to the ramp and ending with the ramp that took the least force. (Continued) 9

12 11. Discuss how changing the length of the ramp affected the force required to pull the car with you group and record your ideas. Did your results support your prediction? 12. Be prepared to share what you learned about the relationship between the length of the board and the force needed to pull the car with the class. 10

13 Student Sheet 1.4 A Levers 11

14 Activity 1.4 Explore Levers Investigation Setup 12

15 Activity 1.4 Explore 1 Levers First Student Procedure: In the next three activities you are going to investigate the effect that using a simple machine called a lever has on the force you apply to the simple machine. 1. Set up the lever system as shown. Your teacher has a model for you to view. 2. Hang washers on the sliding pieces using the metal hangers. 3. Find ways to use the lever system to balance different weights with the lever. 4. See how many washers you can balance with just one washer. 5. Record your observations in your science notebook. Explore 2 Levers Second Student Procedure: In this part of the activity you will balance the weight of five washers on one side with a different number of washers on the other side. 1. Hang 5 washers on the hanger on one side on the fulcrum. 2. Balance the lever by hanging these different weights on the other side of the fulcrum: One washer Three washers Five washers Ten washers 3. Record your observations in your notebook. How did you balance each weight? 13

16 Activity 1.4 Apply Changing the Handle Investigation Setup 14

17 Activity 1.4 Apply Levers Student Procedure: In this activity you will do an investigation to determine the effect changing the length of the effort arm has on the force needed to lift a weight. 1. Paste the chart on student sheet 1.4B in your notebook. 2. Set up a lever with the fulcrum in the middle similar to the one used for the exploration activities. 3. Remove the red rod from both sides of the fulcrum and replace them with white rods. 4. Put gray clips on the end of the rod this time to hang washers on. Hang 10 washers on the end of one of the white rods using the paper clip holder as shown. Throughout this part of the investigation the 10 washer weight will remain on this white rod. 5. Measure the distance from the point where the weight is hung on the rod to the pivot point (fulcrum.) Record the measurement in your chart. It should be the same for each white rod. 6. Hang washers on the other white rod until you lift the ten washer weight. Record the number of washers it takes to lift the ten washers on the other white rod. 7. Replace the white rod without the weights with a blue rod. a. Measure and record the length of the blue rod and the number of washers needed to lift the ten washers on the white rod. b. Repeat this step with a yellow rod, a red rod, and a gray rod. Complete the data sheet. 8. On your whiteboard draw a picture of three levers. Draw them in order beginning with the lever that would take the most effort force to lift a weight and ending with the lever that would take the least force. 9. Be prepared to share what you learned about the relationship between the length of the sections of the lever and the force required to lift the weight? (Continued) 15

18 Answer these questions in your notebook: 1. In this investigation what is the independent variable? 2. In this investigation what is the dependent variable? 3. What variables did we control? 4. What is the relationship between the length of the second rod (handle or effort arm) and the force it takes to lift the weight? 5. Why do you think this is true? 16

19 Student Sheet 1.5A Pulleys 17

20 Activity 1.5 Explore 1 Fixed Pulley Student Procedure: In this activity you will investigate how a single fixed pulley affects the force you apply to it to lift a weight. 1. Using the picture and the model made by the teacher as a guide, construct the pulley system. Tape the pulley holder to your desk top using the masking tape or duct tape. 2. Construct the weight assembly with 10 large washers. 3. Use the spring scale to weigh the weight assembly. Record the force needed to lift the weight in your notebook. 4. Draw a line in your notebook 20 cm long. Place the notebook vertically so that you can pull the string along the 20 cm line. You will pull the string along this line so you will know the distance you pull it. 5. Measure how high the weight goes up when you pull down 20 cm. Compare these distances and record them in your science notebooks. 6. Measure the force required to pull the rope down to lift the weight. (Gravity helps when you pull down because it is pulling on the spring scale. To adjust for this, add the weight of the spring scale to the reading on the scale. Weigh your spring scale with a neighbors scale. The weight should be about.3 to.5 Newtons) 7. Compare the force needed to lift the weight to the weight you recorded earlier. Write observations in the science notebook. Discuss the answers to these questions with your group and record the questions and answers in your notebook. 1. Did the pulley change the distance the forces moved? 2. How did the force needed to lift the weight compare to the force you applied to the string? 3. Why might it be beneficial to use a pulley system like the one that we built? (Continued) 18

21 On your group whiteboard draw and label a fixed pulley system. Show how the fixed pulley affected: The size of the force you applied to the pulley, The distance the force acted and The direction of the force. 19

22 Activity 1.5 Explore 2 Fixed Pulley Build two of these pulleys Build one of these weight holders Build one of these brackets to tape on your desk or table. 20

23 Snap these together. Fixed Pulley Setup 21

24 Activity 1.5 Explore 2 Movable Pulley Student Procedure: In this activity you will investigate how a movable pulley affects the force you apply to it to lift a weight. 1. Construct a moveable pulley assembly as shown and attach the weight assembly with 10 large washers to the bottom. 2. Tie the string to the bar that the fixed pulley was on. 3. Attach the movable pulley to the weight assembly. Run the string through the pulley on the moveable pulley assembly. 4. Draw a line in your notebook 20 cm long. Place your notebook vertically so that you can pull the string along the line. You will pull the rope along this line so you will know the distance you pull it. 5. Lift up on the string up. The weight assembly should move up as well. 6. Measure the distance the weight moves up when you lift the string 20 cm. Write your observations in the science notebook. 7. Predict how much force will be needed to lift the moveable pulley assembly and record your prediction in your notebook. 8. Use the spring scale to check your prediction and record your observations in the science notebook. (You do not need to adjust the reading on the spring scale when you pull up.) On your group whiteboard draw and label a movable pulley system. Show how the movable pulley affected: The size of the force you applied to the pulley, The distance the force acted and The direction of the force. 22

25 Activity 1.5 Apply Movable Pulley Movable Pulley Setup 23

26 Activity 1.5 Apply Block and Tackle Student Procedure: In this activity you will investigate how a block and tackle affects the force you apply to it to lift a weight. 1. Assemble the block and tackle apparatus. This is a combination of a fixed and a moveable pulley. 2. Run the string over the bottom of the fixed pulley. You should now be able to pull down on the string and the assembly should move up. 3. Draw a line in your notebook that is 20 cm long. You will pull the string along this line so you will know the distance you pull it. 4. Measure the distance the weight moves up when you pull the string 20 cm. Write your observations in the science notebook. 5. Predict how much force will be needed to lift the moveable pulley assembly and record it in your notebook. Use the spring scale to check your prediction and record your observations in the science notebook. (Gravity helps when you pull down because it is pulling on the spring scale. To adjust for this, add the weight of the spring scale to the reading on the scale. Weigh your spring scale with a neighbors scale. The weight should be about.3 to.5 Newtons) 6. When you lift the weight you are also lifting the spring scale. Weigh the spring scale (using your neighbors spring scale) and subtract this value form the force required to lift the weight. This will be the actual force needed to lift the weight. On your group whiteboard draw and label these three pulley systems: A fixed pulley system A movable pulley system A block and tackle system Show how the each type pulley system affected the size of the force you applied to the pulley, the distance the forces acted and the direction of the forces. Be prepared to explain how the block and tackle system is a combination of a fixed and movable system. 24

27 Activity 1.5 Apply Block and Tackle Block and Tackle Setup 25

28 Student Sheet 1.6A 26

29 Student Sheet 1.6B 27

30 Activity 1.6 Explore Machines and Tools Student Procedure: In this activity you will examine different types of machines to determine what type of machines they are. 1. Decide with your group whether your tools are simple machines or complex machines. 2. Classify the types of simple machines that you have. 3. Complex machines will contain more than one type of simple machine. Draw a picture of each complex machine that you have. Label the type of simple machines that make up the complex machines. Be prepared to explain your answer. 28

31 Activity 1.7 Explore Identifying the Problem (Engineering Design Step 1) Student Procedure: You are going to compare the energy that you put into a simple machine to the energy output of the machine. First you find the work that you do when you pull washers up an inclined plane. Then you will find the work done by the inclined plane by lifting the washers to the top of the inclined plane. Measuring work is one way of measuring energy. 1. First build a ramp using books stacked about 15 cm high and the board. Measure the length and the height of the inclined plane and record it in your chart. (Student Sheet 6A) 2. Tie twenty large washers together with a string. 3. Use the spring scale to measure the force needed to pull the washers up the ramp slowly and at a constant speed. (Repeat several times so you will get a reliable value.) Record the measurements in the chart. 4. Using the spring scale slowly lift the washers at a constant speed (without using the ramp) straight up to the height at the top of the inclined plane. Record the force required to lift the weights in your chart. 5. Calculate the work done when you pull the washers up the inclined plane. Do this by multiplying the force needed to pull the washers times the length of the board. (This is a measure of the energy you put into the machine.) 6. Calculate the work done to lift the washers straight up. Do this by multiplying the force needed to lift the washers (the weight) times the height of the inclined plane. (This is a measure of the work done by the machine or the energy output of the machine.) 7. Compare the energy that you put into the machine to the energy output of the machine. Which energy is greater? (Continued) 29

32 Identify the Problem 8. If your machine were completely efficient it would transfer all of the energy you put into your machine to output energy for the machine. Why do you think your machine not completely efficient? As a group create a model on your whiteboard that shows what happens to the energy that went into pulling the washers up the inclined plane. Be prepared to present to the class. 30

33 Engineering Design Process 1. Ask questions to identify problems or needs, 2. Ask questions about the criteria and constraints of the device or solutions, 3. Generate and communicate ideas for possible devices or solutions, 4. Build and test devices or solutions, 5. Determine if the devices or solutions solved the problem and refine the design if needed, and 6. Communicate the results. 31

34 Activity 1.7 Apply Building a More Efficient Machine (Engineering Design Steps 2-6) Student procedure: This activity is a design competition. The competition is to design and build the best device to make the inclined plane more efficient to use. Contest Rules: 1. Everyone must use an inclined plane with the same length and height. The inclined plane cannot be changed. 2. The groups may use any of the materials in the materials list to make their inclined plane more efficient. 3. All 20 of the washers must be pulled up the entire length of the inclined plane. 4. The winner is the group who builds a device that requires the least force to pull the washers up the inclined plane. Procedure: 1. Your job is to design and build a device that will make the inclined plane more efficient to use. The challenge is to pull the washers up the inclined plane with the least amount of force possible. 2. Have the material getter get the material for the activity. 3. Set up your inclined plane in exactly the same way the other groups do so that it will be a fair test. 4. Design and build your device to solve the problem. Record the answers to the following questions in your notebook: 1. What force is needed to drag the washers up the inclined plane without your device? (Make this measurement.) 2. What problem do you have to overcome in order to make your machine more efficient? 3. How do you plan to build your device? Draw your planned device. 4. What force was required to pull the washers using your device? 5. How did your device improve (or fail to improve) the efficiency of the inclined plane? Explain. 32

35 Activity 2.1 Ice Cube Race Student Procedure: In this activity each group will place an ice cube in a baggie and try to see how much of the ice they can melt in five minutes. The group that melts the most ice wins. 1. Write the title of the activity and the focus question in your notebook. 2. Have the material getter get an ice cube and a baggie for their group. 3. Each group will place an ice cube in a baggie. 4. Remove as much air as possible and seal the baggie tightly. Sit the baggie on the table until the order is given to start. 5. When all of the groups have their ice cubes in the baggies and are ready, the teacher will begin timing. 6. The groups will have five minutes to melt as much of the ice as possible 7. Place the baggie anywhere you want or do anything to it within reason, as long as the bag remains sealed. 8. Stop and place your baggie on the table when your teacher tells you to do so. 9. Measure the amount of liquid water in your baggie and record the amount in your notebook. 10. Answer the focus question in your notebook. 33

36 Activity 2.3 Explore Heat Transfer by Conduction Investigation Setup Student Procedure: In this activity you will conduct and investigation to determine what will happen to the temperature of hot and cold water if a container of cool water is placed in warmer water. 1. Write your prediction in your notebook. 2. Draw a data table similar to the one on student sheet 2.3A or insert a copy of the sheet in your notebooks. 3. Have the material getters obtain 100 ml of warm water in a Styrofoam bowl and 100 ml of cool water in a plastic cup, and two thermometers. Place the bowl on the tray to avoid water spills. Put the plastic cup in the Styrofoam bowl. 4. Put a thermometer in each cup so you can measure the temperatures of the hot and the cold water. Record the temperatures on your chart at time 0 min. 5. Keep the thermometers in place (one in the small cup and one in the large cup) throughout this investigation. Do not remove them to read them. (Continued) 34

37 6. Measure the temperature of each cup at one minute intervals for 10 minutes and record your readings on the chart in your science notebooks. After you have collected your data: 1. Graph the results on Student Sheet 2.3B. Plot the temperature changes of the hot water with a red pencil and the temperature changes of the cold water with a blue pencil. 2. Did the results support your prediction? 3. What is your evidence? 4. Use your group whiteboard to create a model to explain what happened in the investigation. Draw a picture (model) of the two liquids before and after the investigation. Arrows can be drawn to represent the temperature (speed of the water molecules). 5. Record what you think happened to the thermal energy in each container in your notebooks. 6. Be prepared to explain your model to the class. 7. Have the getters return the cups, thermometers and liquid to the distribution area. 35

38 Activity 2.3 Apply Insulators and Conductors Investigation Setup Student Procedure: In this investigation you will test whether Styrofoam or metal is a better conductor of heat. 1. Write your prediction in your notebook. 2. Draw a data table similar to the one on student sheet 2.3D or insert a copy of the sheet in your notebooks. 3. Have the material getters obtain 100 ml cool water in each of the following: a Styrofoam cup, and a metal cup. 4. Obtain two Styrofoam bowls with 100 ml of warm water each and two thermometers. Place the metal cup in one bowl and the Styrofoam cup in the other bowl. Place a thermometer in both the Styrofoam cup and metal cup. 5. Start timing as soon as you put the thermometer in the water. Record your first temperature reading as the temperature at time 0. (Continued) 36

39 6. Measure the temperature of each cup of cool water at one minute intervals for 10 minutes. The recorder in each group should record the results in his/her data table.) 7. Everyone should complete the data table in their notebook using the recorders table. After you collect the data: Graph the results. [See student sheet 2.3B.] Graph the temperature change for each cup on the same graph. Use different color pencils to graph the temperatures for the different types of cup. What does the graph tell you about which cup allowed more heat to transfer through it? Did the results support your prediction? What is your evidence? 37

40 Activity 2.4 Explore Heating and Cooling Objects by Radiation Student procedure In this activity you will observe heat transfer by radiation. The activity will help you answer three questions. 1. Which will heat up and cool down faster, water or soil? 2. Which will heat up faster, black objects or white objects? 3. What will happen to solar beads in the sun? 1. Write your predictions for each of the questions in your notebook. 2. Have the material getter from each group obtain the materials for the activity. Each group will put 100 ml of water in one cup and 100 ml of dry soil in the other. Two students in your group should be responsible for one cup. 3. Place a lid on each cup and insert a thermometer in the slit. Go outside with the class and place the cups in direct sunlight. 4. Record the initial temperature at time 0 minutes. Record the temperature after each 5 minutes interval for twenty minutes. (Do not remove the tops or shade the cups.) Record your data on Student Sheet 2.4 A according to the teacher s instructions. 5. During the five minute periods between measurements you should work in pairs to do the following activities: Open the envelope containing the solar beads. Divide them equally between the students in your group. Record your observations of the beads reaction to sunlight. Explore ways to change to color of the beads. Place a sheet of white paper and a sheet of black paper on the ground. Place washer weights on the paper to keep the wind from blowing it. Place a thermometer under each sheet of paper to measure the temperature. After the paper has been in the sun for at least five minutes check the temperature under each sheet. Keep testing this while you are outside to see if the temperature changes. 6. At the end of 20 minutes gather the materials and move the water and soil setups to a shaded area (or inside). Do not change the setups. (Continued) 38

41 7. Once in the shade record the temperature. This will be the temperature at time 0 minutes. Record the temperature after each 5 minute interval for twenty minutes to collect the cooling data. 8. Did your data support your predictions? 9. We will analyze the data as a class. 39

42 Activity 2.5 Rain Maker (Solar Still) Investigation Setup 40

43 Activity 2.5 Solar Still Student Procedure: In this activity you will build a solar still to purify water. 1. Have the material getter obtain the materials 2. Construct the solar still. a. Put blue colored water in the bottom of the plastic storage box about 1 cm deep. b. Place the empty cup in the middle of the bowl. Insert a large washer in the cup to hold it down in the water. c. Place a thermometer in the box and lean it against the side so you can read the temperature during the investigation. d. Cover the top of the bowl with plastic wrap and secure with either a rubber band or tape. Make sure the wrap is loose enough so that it will sag when you place the washer in the center. e. Put a weight in the center of the plastic wrap above the cup so that the plastic will sag just above the cup. 3. Place your solar still in full sun. Put a piece of masking tape on your still and label it so you will know which one is yours. 4. Draw your solar still in your science notebook and label the parts. 5. Periodically check the progress of the still. It may be a slow process. Solar stills can be left for several days. 6. When you check your still write you observations in your notebooks. 7. When the teacher tells you, check the temperature inside the still. Compare this temperature to the temperature of the air in the room (or outside if the still is there) and record these temperatures in your notebooks. 8. After the still has run for a while check to see if anything is in the center cup. Record your observations. 9. Draw a model on your group whiteboard to show what happened in your solar still. Be prepared to share the model with the class. Be sure to include what is happening with the water and the radiant energy. 10. When you are finished empty the stills as instructed and have the material getter return the supplies to the materials table. 41

44 Activity 2.6 Explore 1 Transfer of Heat by Convection Student Procedure: In this activity you will observe heat transfer by convection and explain what is happening. 1. Have the material getter get the materials for the activity. 2. Fill the plastic container about two thirds full of room temperature water. 3. Let the water sit until it is completely still. Avoid anything that would jiggle or disturb the water. 4. Carefully place a blue ice cube at one end of the plastic container. Avoid disturbing the water as much as possible. 5. Add a drop of red food coloring to the water at the opposite end of the plastic container. 6. Observe what happens to the color. 7. Discuss with the other members of your group why the color does what it does. 8. Draw what you observe in your notebook using colored pencils. 9. Return your materials as instructed by the teacher. 42

45 Activity 2.6 Explore 2 Student Procedure: In this activity you will cut out a convection snake or pinwheel and use it to detect convection currents. 1. Have the material getter get the materials for the group. There should be a convection detector pattern for each member of the group. 2. Each student should make his/her convection detector. 3. Set up the two bookends and clamp the light to the bookends. 4. After you build your convection detector hold your detector over the light and observe what happens. Describe what happens in your notebook. Write an explanation of why it occurs. 5. Explore different parts of the room to see if you can find any other convection currents. Write your observations in your notebook. Directions for the Convection Snake 1. Cut out the convection snake along the lines. 2. Punch a hole in the center of the snake where the dot is with your pencil lead big enough for your thread to fit through it. 3. Feed the thread through the hole and tape it to the underside of the snake with a small piece of tape. 4. Hold the thread and let the snake hang down. Directions for the Pinwheel 1. Cut out the square. 2. Cut form the corner half way to the center. 3. Bend every other point to the center and tape or staple it. 4. Stick a straight pin through the middle of the pinwheel and into a pencil eraser. 43

46 Activity 2.6 Apply Transfer of Heat by Convection Student Procedure: Read the passage below describing why wind blows and follow the directions after the reading. When air begins to move, it becomes wind. Wind is a convection current caused by uneven heating of the earth. A light breeze springs up when air moves slowly. Gales and hurricanes tear through the skies when air moves very quickly. Slow or quick, winds always begin the same way, with a difference in air pressure caused by uneven heating. Wherever the air is cold and denser it tends to sink, increasing the pressure. Sinking cold air pushes the warmer air up. Wherever air is warmer and lighter than the surrounding air, it tends to rise, reducing air pressure. Winds blow from high-pressure zones to low-pressure zones. You will make a drawing to predict and show land and sea breezes. Remember that wind is a convection current. As we saw in Activity 2.4, land and water do not heat up at the same rate. Water heats up more slowly than land does during the day. Therefore water is cooler than the land during the day. The air above the water is cooler than the air above the land as well. Make a drawing on your whiteboard showing the ocean and the shore. Draw arrows that indicate the convection current that forms during the day. Water gives off heat more slowly than land so the water is warmer during the night. Draw arrows in a different color to show the convection current that forms at night. Copy these questions in your notebook and answer them after you have talked this over with your group. 1. Does the wind blow towards the land or towards the water during the day? Explain. 2. At night which way does the wind blow at the beach? Explain. 44

47 Activity 2.7 Save the Cube Student Procedure: You will plan and build an Ice Preserver. The group that preserves the ice cube the longest wins. 1. The first step in the engineering design process is to identify the problem that needs to be solved. Decide what problem we need to solve to prevent the ice cube from melting and record this in your notebook. 2. Plan an Ice Preserver using the materials on the table. Write the plan in your notebook. 3. After every group has planned their Ice Preserver, have the material getter get the materials you need. 4. Build you Ice Preserver. 5. After every group has finished with their Ice Preserver, have the material getter get an ice cube. Place the ice cube in the Ice Preserver and finish preparing it. (Make sure you can get into your Ice Preserver to check on the health of your ice cube.) 6. When your Ice Preserver is ready find a place that you think will be best to store it. (Hint: Remember all of the ways that heat is transferred.) 7. Draw a picture on your whiteboard that illustrates each type of heat transfer and how your Ice Preserver will prevent each type. 8. Plan a presentation with your group to explain each method of heat transfer and how you planned to stop it with your Ice Preserver. 45

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49 Activity 3.1 Explore 1 Complete Circuits Student Procedure: In this investigation you will explore how electric circuits work. 1. Have the material getter pick up the materials. Your group needs a battery, two wires, and a light bulb. 2. Let two members of your group find a way to make the light bulb light while the other two watch. 3. Give the materials to the other two members and let them find a different way to make the light bulb light. 4. Take turns until your group finds at least four ways to make the bulb light. 5. In your science notebook record your observations. Draw one of the complete (or closed) circuits that made the light bulb light. Draw at least one circuit that did not work. Answer the following questions in your science notebook: 1. Explain how you lit the light bulb. 2. What type of energy goes into the bulb? 3. What is the source of the energy? 4. What types of energy come out of the bulb? 5. Where does it go? 46

50 Activity 3.1 Explore 2 Transformations in Electric Circuits Student Procedure: In this investigation you will explore energy transformations in electric circuits. 1. Build a circuit which includes: 1 battery in a battery holder 3 wires 1 switch 1 motor 2. Be sure that the motor will turn on and off when the switch is opened and closed. 3. Draw the circuit in your science notebook. 4. Observe and record the energy transformations in the Energy Device Chart in your notebook. 5. Remember to use all of your senses for observations. 6. Replace the motor with a buzzer. Close the switch. (Leave the buzzer on just long enough to observe the energy transformation.) 7. Observe and record the energy transformations. 8. Discuss the chart with your partners and answer the questions in your chart. 9. What kind of energy does most of the energy in the circuit eventually become? 47

51 Activity 3.2 Explore Sources of Electric Energy Students Procedure: In this activity you will explore the energy transformations in electric circuits that use three different sources of electric energy. Station 1: Generator Use these materials to build a circuit to run an electric motor with a generator. Caution! The generators will break easily if not handled properly. The students should start turning the generators slowly and gradually increase the rate that they turn the handle. Turning the handle too fast or rough handling could break the generator. Hand-held generator 2 alligator connectors 1 motor Record the answers to these questions in your notebook. 1. What is the evidence that energy is in the circuit? 2. What provides the energy for the circuit? 3. Try to vary the amount of energy that is in the circuit. Describe how you do it. 4. In your notebook draw the circuit. Show the devices and label the type of energy that goes in each device and the energy that comes out. 48

52 Station 2: Solar cell Use these materials to build a circuit to run an electric motor with a solar cell. Caution! The 100 Watt bulbs get very hot. Do not touch them. 1 solar cell 2 alligator connectors 1 motor 1 light bulb, 100 W (for clamp lamp) 1 clamp light with reflector 2 bookends (to hold the light) Record the answers to these questions in your notebook. 1. What is the evidence that energy is in the circuit? 2. What provides the energy for the circuit? 3. Try to vary the amount of energy that is in the circuit. Describe how you do it. 4. In your notebook draw the circuit. Show the devices and label the type of energy that goes in each device and the energy that comes out. Station 3: Batteries Use these materials to build a circuit to run an electric motor with a battery. 2 batteries 2 battery holders 3 alligator clip connectors 1 motor Record the answers to these questions in your notebook. 1. What is the evidence that energy is in the circuit? 2. What provides the energy for the circuit? 3. Try to vary the amount of energy that is in the circuit. Describe how you do it. 4. In your notebook draw the circuit. Show the devices and label the type of energy that goes in each device and the energy that comes out. 49

53 Activity 3.2 Apply Exploring Batteries Student Procedure: In this investigation you will explore how batteries work. 1. Have the materials getter from your group obtain the materials. 2. In the first procedure we will build a chemical cell sometimes called a battery. For this activity you will need: 1 multimeter 2 alligator clips 1 small cup 5 grams of salt (approximately) 1 bag containing different types of metals 1 group whiteboard 3. Pour the salt into the cup and add about 50 ml of water. Stir the water. 4. Clamp one alligator clip to the red wire of your meter and another to the black wire. 5. Connect one of the metals to each alligator connector. 6. Set the dial of the meter to the 2V setting. This will measure the electric voltage that you get from the chemical reaction and shows you that you are producing electric energy. Voltage is a measure of the electric potential energy or stored electric energy. 7. Put both metals into the salt water in the cup. 8. Make a chart similar to this one to record your results. 9. Try at least two other combinations of metals of your own choosing and add the results to the chart. Test Materials Copper and Zinc Paperclip and Aluminum foil Paperclip and Copper Penny and Nickel Voltage (volts) (Continued) 50

54 After the investigation: Graph the data in your notebooks and on your group whiteboard. Record the answers to these questions in your notebook. 1. In the investigation you have just done, what is the independent variable? 2. What is the dependent variable? 3. Which combination of metals stored the most electric energy? 4. What do you think determines the voltage of the battery? 5. What type of graph should you use to graph the data in your chart? Why? 51

55 Activity 3.3 Explore 1 Magnetic Fields Student Procedure: In this activity you will explore an invisible force field called a magnetic field and share what you learned. 1. Have the material getter pick up the box with the materials for the investigation. 2 magnets 1 compass 1 iron bolt 2. Explore the magnets to see what effects they have on each other and on the other materials that you have. Make sure each member of the group has a chance to explore all of the materials. Write your observations in your notebook. 3. Use your materials to determine the shape of the invisible magnetic field around one of the magnets. 4. Draw a representation of your magnetic field on your white board. 5. Be prepared to explain how you could tell the shape of the magnetic field and where the invisible field was located. 6. Arrange your magnets on your desk or table in such a way that there will be energy stored in the magnetic fields of the magnets. Check with your teacher to make sure that you can demonstrate that there was energy stored in the magnetic field of your magnets. Record the answers to these questions in your notebook. 1. What effects do magnets have on each other? 2. What effect does a magnet have on the bolt? 3. What effect does a magnet have on the compass? 4. Do you think a magnetic field has a direction? Explain. 5. How would you define a magnetic field? 6. What was your evidence that energy could be stored in a magnetic field? 52

56 Activity 3.3 Explore Electromagnets Student Procedure: In this investigation you will build an electromagnet and explore how it works. 1. Have the material getter pick up the box with the materials for the investigation. 2. Build an electromagnet. a. Wrap wire around the iron bolt leaving about 5 centimeters of the wire unwrapped on each end. (Hint: always wrap the wire in the same direction for best results.) b. Build an electric circuit with a battery in a battery holder, a switch and the bolt with the wire wrapped around it. 3. Explore ways that the electromagnet affects the items in your box such as the paper clips, the magnet, and the compass and record your observations in your notebook. (Hint: don t leave the switch closed too long. The battery will burn out quickly.) 4. Try opening and closing the switch. What changes in the effects do you observe? 5. Try switching the connections on the electromagnet. What change of the effects do you observe? 6. See if you can make the compass spin with the electromagnet. Can you think of a practical application? 7. Create a model describing how an electromagnet works. Draw it on your group whiteboard and label it so you can present it to the class. Be sure to include the concept of a magnetic field. 53

57 Activity 3.3 Apply Activity Setup Student Procedure: In this activity you will explore ways to spin a device using magnetic force fields. 1. Have the material getters get the materials for the activity. 2. Using K NEX pieces, build a device to hold the small bar magnets as shown. 3. Using the third magnet, see if you can make the other magnets spin without touching them. 4. Place the compass beside the magnet spinner. Observe what happens. 5. Use the electromagnet and circuit from the previous activity. Explore ways to make the magnets spin using your electromagnet without touching the bar magnet. 6. Can you move the device simply by turning on the electromagnet? 7. In your notebook explain how you were able to get the apparatus to move without touching it. 8. Can you think of a practical application for spinning magnets with other magnets? 54

58 Activity 3.4 Explore Electric motors Student Procedure: In this investigation you will explore how an electric motor works. First Procedure: 1. Have the material getter pick up the materials. 2. Put the propeller on the motor. 3. Construct a circuit with the motor, a switch, a battery holder and a battery. 4. Close the switch. Observe the motor. 5. What is the energy transformation that you observe? Record this in your notebook. 6. From what you have already learned in the last activities and from what you observe, predict what is inside the motor that makes it spin. 7. Record this prediction in your notebooks. Second Procedure: 1. Take the cover off the motor so that you can see inside. To do this, follow the following procedures: Remove the propeller from the motor. With a nail straighten the two tabs at the back of the motor. Hold the case and push the long shaft. The case should slide off. 2. Draw the parts of the motor in your notebook. 3. What do you think each part is for? Record your ideas in your notebook. 55

59 Activity 3.4 Apply Making a Motor Student Procedure: In this investigation you will explore how the parts of a motor work. First Procedure: Magnetize the Electromagnet 1. Have the material getters get the materials for the activity. 2. Find the part of the motor that acts as an electromagnet. 3. Place the battery in the battery holder. Connect the two wires to the battery holder. 4. See if you can magnetize the electromagnet. Use paper clips to determine if it magnetizes. 5. Record in your notebook which part the electromagnet is and how you were able to magnetize it. (Continued) 56

60 Activity 3.4 Apply Making a Motor Armature Support Setup Second Procedure: In this part of the activity you are going to build a motor and then test ways to change the way the motor runs. 1. Build the K NEX apparatus as shown for holding the armature that we used in the first procedure. 2. Twist the no. 20 wires together near the end and make a V as shown. Make sure the bare parts on the wires do not touch. 3. Use tape to hold the wires on the apparatus. Secure the wires to the K NEX stand as shown. 4. Connect the circuit. 5. Place the armature in the stand and bend the wires so that it is secure. Can you decide which part needs to rest in the V? 6. Hold one of the magnets near the armature and close the switch. The armature should move. If it does not adjust your apparatus until you can make it move. (Continued) 57

61 7. Using two magnets, explore ways to make the motor spin. Can you make it spin fast? Can you make it spin slowly? Can you make it spin in the opposite direction? 8. Create a model describing how an electric motor works. Draw it on your group whiteboard and label it so you can present it to the class. Be sure to include the concept of magnetic fields. 58

62 Activity 3.5 Explore 1 Changing Mechanical Energy to Electrical Energy Student Procedure: In this investigation you will explore ways to change mechanical energy into electric energy. 1. Make a coil with the 2 meter piece of 22 gauge connector wire by wrapping it around the bolt very close to the head of the bolt. 2. Connect the ends of the coil to the meter with the alligator clip connecters. Set the meter on 200 A. The meter will indicate when electric energy is produced even if it is just a small amount of electricity. 3. Using the coil and the magnet try to produce an electric current. 4. What were you doing when you made the most current? 5. Is there a way that the magnet can be held near the coil without producing a current? 6. In your science notebook record the way that you produced electricity. 7. When did the meter register an electric current? 8. What energy transformations occurred when you made the electricity? 9. Create a model describing how you transformed the energy. Draw it in your notebook and label it. Be sure to include the concept of magnetic fields. 59

63 Activity 3.5 Explore 2 Changing Energy with a Motor Student Procedure: In this investigation you will explore ways to transform mechanical energy into electric energy using a motor. 1. The material getters should pick up the materials for the group. 2. Using two alligator clip connectors, connect one of your motors to the multimeter and set the meter on 2000 A. 3. Try to make the motor produce electricity in different ways. 4. Stretch a wide rubber band across the edge of a book. Run the armature shaft along the rubber band and observe the meter. 5. Record your observations in your science notebook. 6. Connect two motors together using alligator connectors. Put a propeller on one motor. Run the armature shaft of the other motor along the rubber band. 7. Write your observations in your science notebook. 8. What energy transformations did you observe? 9. Make a circuit with the motor, the light bulb, and light socket and two alligator connectors. Try to light the bulb using the motor. 10. Write your observation in your notebook. 11. What energy transformations did you observe? 60

64 Activity 3.5 Apply Electric generators Student Procedure: In this activity you will explore how generators produce electric energy and explore the relationship between motors and generators. Caution! The generators will break easily if not handled properly. 1. Have the material getters obtain the materials. 2. Examine the parts of the hand-held generator. Notice the motor inside. What parts in the motor are important in generating the electric energy? 3. Discuss these questions with your group. What simple machines are in the generator? How do you think the simple machines help make the generator work better? 4. Make a circuit with the hand-held generator, a light bulb holder, and a light bulb. Use the generator to light the bulb. 5. What is the energy transformation in your circuit? 6. Vary the speed that you turn the generator and observe what happens. How does changing the amount of energy that you give the generator affect the amount of light energy that you produce? 7. Make a circuit with the hand-held generator and a motor with a propeller on it. 8. Change the direction and speed that you turn the generator. How does this affect the motor? 9. Next you will work with another group. Wait for the teacher to explain what you will do. 10. After you have done the activity in which you hooked the two generators together. Create a model describing how a generator works. Draw it on your group whiteboard and label it so you can present it to the class. Be sure to include the concepts of: Motion (mechanical energy) Electric energy Magnetic fields 61

65 Activity 3.6 Explore Electric Power Plant Model Generator 62

66 Activity 3.6 Explore Electric Power Plant Student Procedure: In this activity you will construct a model of a power plant and explore ways to make it generate electricity. 1. Have your material getter pick up the materials for the activity. 2. Construct the model of the electric power plant as shown. Make sure the magnet in your model will spin. 3. Check to see if your power plant can produce electricity. To do this, wrap a tight coil of wire near the end of your bolt using a piece of wire 2 meters long. Using alligator clips connect the ends of the wire coil to the electric meter. Set the multimeter on the 200 A setting. Using your fingers, spin your apparatus that holds the magnet. Hold the coil very close to the spinning magnet. Does the meter indicate that electrical energy is being produced? What energy transformation do you observe? 4. Electric power plants use different kinds of energy to spin a magnet. Your job is to find as many ways as you can to spin the wheel and the magnet without touching it with your hands. Use the materials you have to spin the wheel without touching the apparatus with your hands. (If you use the water, make sure the model power plant is in the pan so you don t get water on the table or floor.) 63

67 Activity 3.6 Apply Electric Power Plant Student Procedure: In the first part of this activity you will learn how some of the electric power plants that are used today work. In the second part of the activity you will design an alternative power plant and present your solution to the class. Part 1: 1. Refer to the pictures of the different types of electricity generators. Examine the design of each type of power plant and read about how each one works. 2. Discuss with your group how each type of plant works. 3. Describe the energy transformation for each type of power plant in your notebook. 4. When you are finished with this part of the activity your teacher will lead a discussion about what you learned so far. Hydroelectric Plant The water is held in a reservoir, or lake, behind the dam. The water is held at a higher elevation than the turbine, so that it can fall with enough force to strike the turbine s blades and cause it to spin. The turbine wheel is attached by a shaft to a system of magnets and wires called a generator. As the turbine rotates, magnets spin inside a coil of wires which produces electricity. (Continued) 64

68 Coal Power Plant Coal is burned to heat water and turn it into steam. The enormous pressure of the steam pushes against a series of giant turbine blades which turn the turbine shaft. The turbine shaft is connected to the shaft of the generator, where magnets spin within wire coils to produce electricity. Natural Gas Power Plant Natural gas combustion turbines operate differently from coal-fired plants. They do not use steam to drive a turbine. They are similar to a jet engine. Combustion turbines spin because the heated air from the burning of natural gas expands and pushes the blades in the turbine. The turbine is a series of many long, thin blades similar to propeller blades. The expanding air pushes the turbines much like steam does in a steam-electric station. The energy from the spinning blades spins the electric generator. 65

69 Part 2: Electric power plants produce the electricity we need for our homes, schools and businesses. In order to produce this electricity we must use energy from different sources. Your job in this part of the activity is to design a power plant that uses an energy source different from the three types you learned about in part 1 of this activity. Remember the generator in a power plant is connected to a turbine. A turbine has blades on a shaft like a fan or propeller. A moving fluid (water, wind, steam, etc.) acts on the blades so that they rotate and spin the generator. In this activity you will use the first three steps in the engineering design process listed below. Engineering Design Process 1. Ask questions to identify problems or needs, Examples of questions: What fluid can we use to turn the turbine? Does the fluid already have energy? If not how can we add energy to the fluid? Is a fuel needed? 2. Ask questions about the criteria and constraints of the device solutions, Examples of questions: Is the fuel available and inexpensive? Does the device need to produce electric energy at all times? Will the device be harmful or helpful to the environment? 3. Generate and communicate ideas for possible devices or solutions, Draw a picture or diagram on your whiteboard that represents the electric power plant that you designed. Present it to the class. (Continued) 66

70 In your picture be sure to include: The generator (with the parts drawn) The energy source The turbine The type of fluid (water, steam, wind, etc.) that turns the turbine. Any other parts needed for the type of plant that you designed. The presentation should include: The problems or needs solved by the design The criteria or constraints of the design How you power plant works The energy transformations that occur Why you think your design would be a beneficial way to generate electricity 67

71 Activity 4.1 Conservation of Energy Student Procedure 1: Energy Transformation Game In this activity you will play the energy transformation game and learn some of the ways energy might transform from solar energy into other useful types of energy. 1. Have the material getters pick up the energy transformation cards. 2. Spread the cards out on the surface that you will play the game on so that everyone can see the cards that are in the deck. 3. Refer to your Energy Reference Sheet to see what each card means. 4. Take turns reading the reference sheet. Read an item description and then find a card that matches the description. Go to the next person in the group who will read the next item and find the card to match. Continue until you have gone through the two pages of the reference sheet. 5. The rules of the game are printed after the energy reference sheet in your. 6. Use your deck of energy cards to play the Energy Transformation game. (Continued) 68

72 Rules of the game: 1. This game is played similar to dominoes. You must play the same pictures beside each other and then explain the energy transformation. 2. The arrows indicate the direction of the transformation and the direction that the cards must be placed in. You may play on more than one side of a card as long as the card played only touches one card. 3. Place the double sun card in the middle of the playing area. 4. Deal five cards to each player. 5. The player to the right of the dealer will play first. If the player has a sun card he/she can play it on the double sun. If the player does not have the card he/she must draw a card from the deck. The next player will play if he/she has a matching card. If not he/she should draw a card and the next person plays and so on. 6. Once a card is played the next player must place a card beside one of the matching cards as in dominoes. That player must explain his/her move to the other players. If the other players do not agree that the explanation is correct the player loses his/her turn. 7. A player may place a card on any open side of a played card as long as the card played only touches the card it is played on. 8. Continue moving to the right after each card is played. 9. The energy reference sheet explains the cards and may be used at anytime to help understand the types of energy and devices. 10. The player to run out of cards first wins! Your teacher may allow you to play more games as time allows. Student Challenge 1. Working with your team, arrange of your transformation cards so that all of them are played. 2. Be prepared to explain all of the transformations when the teacher asks you to. (Continued) 69

73 Energy Reference Sheet Solar Energy: The earth receives energy from the sun in the form of light and radiant heat energy. Most of the energy we use comes from the sun. Plants: Plants receive light energy from the sun and through a process called photosynthesis store that energy in sugars which are used to make plant tissues and food for the plant. This energy is stored as chemical energy. Oil: Oil is a fossil fuel. It has chemical energy stored in it. It was formed from plants and animals that died and were buried in the ground millions of years ago. Over time these plants and animals turned into oil which still has some of the chemical energy that was originally stored by the plants when they were alive. It can burn and release heat energy. Natural Gas: Natural gas is a fossil fuel. It has chemical energy stored in it. It was formed from plants and animals that died and were buried in the ground millions of years ago. Over time these plants and animals turned into natural gas which still has some of the chemical energy that was originally stored by the plants when they were alive. It can burn and release heat energy. Coal: Coal is a fossil fuel. It has chemical energy stored in it. It was formed from plants that died and were buried in the ground millions of years ago. Over time these plants turned into coal which still has some of the chemical energy that was originally stored by the plants when they were alive. It can burn and release heat energy. Light energy: Light energy can come from the sun or light bulbs. It can be changed to chemical energy by plants. It can also be transformed into electric energy using solar cells. Wind energy: When the sun heats the earth it heats it unevenly. This produces convection currents. Wind is a convection current. Heat energy: Heat energy may come from the sun or other sources. When materials receive heat energy the temperature increases and the particles in the materials move faster. 70

74 Potential energy in water behind a dam: When the sun heats water it evaporates and can precipitate in the form of rain or snow at higher elevations. This is part of the water cycle. At higher elevations the water has potential energy. It has the potential to flow downhill as moving water which has kinetic energy. The moving water can be used to turn a turbine. Solar cell: A solar cell is a device that changes light energy to electric energy. Electric energy: Electric energy can be produced by a generator, a solar cell, or by a battery. It can be transformed into many other types of energy. Generator: A generator uses magnets and a coil of wire to change kinetic mechanical energy to electric energy. Turbine: A turbine is a device like a propeller, water wheel, or a fan. It can be turned by water, steam, or wind. A turbine can be used to turn a generator. 71

75 Activity 4.2 Explore Solar Cells Student Procedure: In this investigation you will explore the factors that affect the amount of electric energy produced by solar cells. 1. Have the material getter pick up the materials for the investigation. 2. Attach the propeller to the motor and connect the photovoltaic cell to the motor using the alligator clip connectors. 3. Take your solar powered system outside and activate them in the sunlight. 4. While outside explore factors that affect the spin of the motor. Points you might want to investigate could include: What happens when the panel is turned away from the light? What happens when part of the panel is shaded with your hand? How much of the panel can you shade before the motor stops? Observe the rotation of the propeller blades to see which way they are turning? What happens when the wires are attached the opposite way (red to black)? 5. Does the angle of the cell in relation to the sun make a difference in how fast the propeller turns? Use your protractor to estimate the angle which produces the most electricity. Let the teacher check your measurement. 6. What happens when the two alligator clips touch? 7. Attach the multi-meter and see how many amperes of electric current your cell is producing. Try setting the meter on the 10A setting. Plug one wire into the hole labeled COM and the other wire in the hole labeled A. 8. Explore some of the ways you can change the number of amperes that the cell is producing. Repeat the things you tried with the motor. 9. Were the results similar to the results you observed using the motor? 10. What might be the advantage of using a multimeter instead of a motor to test the effects of different factors on the electricity produced? 11. Try wiring two cells together to see what affect this has on the electricity produced? (You may need to try different settings on the meter to measure this.) 12. Write your observations in your notebooks. 72

76 Activity 4.3 Solar Panel Data Explore 2 Student Procedure: In this activity you will explore the data from solar panels located at different schools. Pull up the website for your school or go to: and select a school. Explore the website to see what information you can find. Record the answers to the following questions using the data on the website in your notebook. [Hint: use complete sentences that include part of the question so you will know what question goes with what answer.] 1. How much power is your system generating right now? [Hint: power is measured in Watts, symbol W or in kilowatts, symbol kw. One kilowatt equals 1000 Watts.] 2. How much electric energy did your solar panel produce last month? [Hint: electric energy is measured in Watt-hours, symbol Wh or kilowatt-hours, symbol kwh. A kilowatt-hour is 1000 Watt-hours.] 3. How much electric energy has your solar panel produced since it began operating? 4. What time of day did the panel produce the most power? 5. When is no power being produced? Why do you think no power is being produced? 6. Why do you think this might present a problem for using solar power to power our homes? 7. Was the electrical energy produced on some days different from the energy produced on others? Why do you think this is true? 8. Why do you think this difference might present a problem for using solar power to power our homes? 9. How much carbon dioxide has your school s solar panel avoided creating since it was installed? 10. Why do you think this might be considered important? 73

77 Activity 4.3 Apply Variables in Solar Energy Production Student Procedure: In this investigation your group will be given a graph that represents data from a solar panel. Your job will be to make a presentation to explain the story to explain your graph. You will make inferences based on the data that the graph represents to develop the story. The teacher will assign each group a graph to analyze. The graphs show electric power transformed from light power by a solar panel during different times of day. Line graphs are used because the electric power produced continually changes at different times of day. Presentation: You will need to use your whiteboard to make your presentation. Draw your graph on your whiteboard. Label it in a way that will help you tell your story. The solar panels that were used to collect the data can produce as much as 2 kilowatts or 2,000 Watts of power if conditions are just right and they are operating at peak efficiency. Things to include in your story of the graph: 1. What was the weather like while the data was being collected? 2. What is the evidence for your claim about the weather? 3. When did the solar panel start producing power? 4. Why was there no power produced earlier in the day? 5. When did the solar panel stop producing power? 6. Why did it stop producing power? 7. What problems would you have to overcome if the solar panels were your only source of power? 8. How might you overcome the problems? When you have completed your whiteboard and presentation preparation the teacher will call the class together. 74

78 The data for the graph below was taken from the solar panel at Hillcrest Middle School on August 20, The data for the graph below was taken from the solar panel at Myrtle Beach Middle School August 13, The data for the graph below was taken from the solar panel Hilton Head middle school August 12, The data for the graph below was taken from the solar panel Sangaree Middle School August 21,

79 The data for the graph below was taken from the solar panel Plainview Elementary School July 24 through July 25, The data for the graph below was taken from the solar panel at Hardeeville- Ridgeland Middle School August 19 through August 20,

80 The data for the graph below was taken from the solar panel at Muller Road Middle School August 20 and August 21, The data for the graph below was taken from the solar panel at Merriwether Middle School August 17 and August 18,

81 Activity 4.4 Solar Derby Student Procedure: Your team is now a team of engineers who must prepare a car for the upcoming Solar Derby. You must harness the energy of the sun to make your car go. 1. Begin by giving each member of the team some specific responsibilities. You might use responsibilities such as a. Chief engineer: oversees the whole building process, makes sure that all members of the team are involved, and delegates jobs to others. b. Test driver: sets up the car for trial runs, coaches the final drivers in how to run the car. c. Construction engineer: Oversees the actual building of the car itself, selects others to build parts of the car, assembles the final car or asks someone else to do it. d. Timer: Practices with the stop watch so he/she can time the trials, records time trial data to help the team decide which designs work best. e. Driver: This job should be done by each member of the team in a rotation. Each member should take a turn driving the solar car if possible. 2. Build your car like the model in the photos and like the one your teacher constructed. 3. Label your car with the names of your team using masking tape. [Hint: you may want to use one big label and another smaller label just in case one label falls off.] 4. Make two or more trial runs. Using masking tape mark off a test track at least 4 meters long. Use your stop watch to decide the speed of your car. Record the time that the unmodified car completes the test run in your notebooks. (A shorter time means a faster speed.) 5. Once you are sure that your car can run dependably, you can make one or more changes to improve its performance. You will have time today and during the next science class to make some final changes in your vehicle to improve its speed. 78

82 Activity 4.4 Solar Derby 79

83 Activity 4.4 Solar Derby 80