BLM 4-1, Class 1, 2, and 3 Levers/ Overhead Master. BLM 4-2, Levers Have Class/ Reinforcement. BLM 4-4, Mechanical Advantage/ Reinforcement

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1 TOPICS 1 3 BLM 4-1, Class 1, 2, and 3 Levers/ Overhead Master not applicable BLM 4-2, Levers Have Class/ Goal: Students identify items as Class 1, Class 2, or Class 3 levers. 1. Class 1 6. Class 2 2. Class 3 7. Class 1 3. Class 2 8. Class 3 4. Class 1 9. Class 3 5. Class 1 BLM 4-3, What is Work?/Problem Solving Goal: Students practice using and applying the scientific definition of work to everyday situations. 1. (a) 100 (b) 50 (c) 20 (d) 10 (e) 2 (f) 1 2. (a) f, 1 < 100 (only 1 N of force was needed). (b) a, it only took 1 m of distance. 3. W = 800 N 0m = 0J 4. W = 2210 N 1.5m = 3315 J = 3.3kg 4. The work done for the job, no matter which ramp is used, is the same because the height reached is the same. However, the force is spread over a longer distance with ramp B. If the distance increases, then the force required to get the same work decreases. W = F d F = 60 kg + 2kg= 62 kg = 620 N d = 2.5 m = 620 N 2.5 m = 1550 J = 1.55 kj 6. W = 0. The sidewalk did not move. 7. Answers will vary. Sample solution: Mass = 70 kg = 700 N. Jump height = 50 cm = 0.5 m W = 700 N x 0.5 m = 350 J 8. Answers will vary. 9. Whichever form of exercise uses more joules is the better workout. BLM 4-4, Mechanical Advantage/ Goal: Students reinforce their understanding that mechanical advantage can be calculated in a similar way for all machines. not applicable BLM 4-5, Wheels, Axle/ not applicable BLM 4-7, Turnaround Time/Science Inquiry Goal: Students record their results for Find Out Activity: Turnaround Time. 1. Answers will vary. 2. See page TR4-32 in the Teacher s Resource. BLM 4-6, Wheel and Axle/ Goal: Students review how the wheel and axle and the lever are machines that work in similar ways. The steering wheel is a class 2 lever and the car tire is a class 3 lever. 5. You may need to remind students that the student in the example went up to the second floor as well as the balloon. This page may be reproduced for classroom use by the purchaser of this book without the written permission of the publisher. 231

2 TOPICS 1 3 BLM 4-7, Turnaround Time/Science Inquiry Goal: Students record their results for Find Out Activity: Turnaround Time 1. Answers will vary. 2. See page TR4-32 in the Teacher's Resource. BLM 4-11, Easy Lifting/Science Inquiry Goal: Students record their results for Inquiry Investigation 4-D: Easy Lifting. Answers to the Analyze questions and Conclude and Apply questions can be found on pages TR4-54 and 4-55 of the Teacher s Resource. BLM 4-8, Gear Up for Speed!/ Science Inquiry Goal: Students record their results for Inquiry Investigation 4-B: Gear Up for Speed! 1. Answers will vary. 2. See page TR4-37 in the Teacher s Resource. BLM 4-9, Pulley Power/ Goal: Students review the different types of pulleys and their mechanical advantage (MA). 1. (a) 1 fixed pulley, 0 movable pulleys, MA = 1 (b) 0 fixed pulleys, 1 movable pulley, MA = 2 (c) 1 fixed pulley, 1 movable pulley, MA = 2 (d) 1 fixed pulley, 2 movable pulleys, MA = 4 2. Answers will vary. BLM 4-10, Efficiency Calculations/ Problem Solving Goal: Students review the formulas for calculating efficiency and work percent percent percent BLM 4-12, Mechanical Advantage Problems/ Problem Solving Goal: Students review how to calculate the mechanical advantage of various simple machines. Hints & Helps: This BLM could be used as either a review or a test. If you use it as a test, assign one mark per question N N BLM 4-13, Simple Machines Cryptic/Vocabulary Check Goal: Students review words and terms introduced in Topics 1, 2, and lever 6. sprocket 2. ergonomics 7. pulley 3. load 8. work 4. gear 9. driver 5. inclined plane 10. winch 11. wheel and axle 12. pulley 13. speed 14. fulcrum 15. block and tackle 4. (a) A machine is never 100 percent efficient because some work is always lost to friction. This work is then turned to sound or heat energy. (b) Lubricants may be used to reduce the amount of friction, but the efficiency will never be 100 percent. 232 This page may be reproduced for classroom use by the purchaser of this book without the written permission of the publisher.

3 TOPICS 1 3 BLM 4-14, Topics 1 3 Test/ Goal: This quiz can be used to assess students understanding of concepts learned in Topics lever 6. wheel and axle 2. fulcrum 7. pulley 3. ramp 8. gear 4. mechanical advantage 9. fixed 5. efficiency 10. movable 11. (b) 12. (a) 13. (c) 14. (a) 15. (b) 16. A pair of scissors uses levers and wedges (the blades). 17. A nail gun is a powerful tool because it propels the nails into the wood at a great force. It does the job quickly and efficiently. 18. The shorter ramp may be quicker, but a greater force is needed to move the piano. The longer ramp requires a smaller force but may not fit in the required space. This page may be reproduced for classroom use by the purchaser of this book without the written permission of the publisher. 233

4 TOPICS 4 6 BLM 4-15, Pascal s Law/Overhead Master not applicable 1. Students sketches may be similar to those below. Water in the System Air in the System BLM 4-16, Pascal s Law and Mechanical Advantage/ x x x x Goal: Students review Pascal s law and the calculation of mechanical advantage cm m 4. Answers will vary. BLM 4-17, What a Lift!/Science Inquiry Goal: Students organize their findings for Think & Link Investigation 4-F: What a Lift! 1. and 2. Answers will vary. See page TR 4-72 in the Teacher s Resource. 3. and 4. See page TR4-72 in the Teacher s Resource. 5. Answers will vary. BLM 4-18, Build Your Own Hydraulic Lift/Science Inquiry Goal: Students record their design and results for Problem-Solving Investigation 4-G: Build Your Own Hydraulic Lift. 1. to 3. Answers will vary. 4. See page TR4-72 in the Teacher s Resource. 2. (a) The water particles are relatively close together compared with the air particles. There is more resistance, resulting in a slower flow rate. (b) The air particles are relatively far apart compared with the water particles. There is less resistance, resulting in a faster flow rate. BLM 4-20, Redesigned Hovercraft/ Science Inquiry Goal: Students redesign the hovercraft they built in Find Out Activity: Build a Model Hovercraft. Answers will vary. BLM 4-21, Word Hunt/Vocabulary Check Goal: Students reinforce their understanding and use of terms related to pneumatics and hydraulics. Answers will vary. BLM 4-22, Braking and Robotic Systems/Overhead Master not applicable BLM 4-19, Comparing Pressure Exerted on a Gas and on a Liquid/ Goal: Students organize their findings for Inquiry Investigation 4-H: Comparing Pressure Exerted on a Gas and on a Liquid. This page may be reproduced for classroom use by the purchaser of this book without the written permission of the publisher. 249

5 TOPICS 4 6 BLM 4-23, Rube Goldberg Balloon Popper/Design Your Own Investigation Goal: Students design their own instructions for a machine that can pop balloons. Answers will vary. BLM 4-24, New, Improved Robots Required!/ Goal: Students develop a rubric to evaluate the robots they designed in Problem-Solving Investigation 4-J: New, Improved Robots Required! not applicable BLM 4-25, Topics 4 6 Test/ Goal: Students assess their understanding of the concepts they studied in Topics Force 6. kilopascal Area 2. F 7. hydraulic A 3. newtons 8. closed 4. m 2 9. fluid 5. pascal 10. pneumatic 11. (c) 12. (d) 13. (c) 14. (c) 15. (d) 16. Pascal s law states that pressure exerted on a contained fluid is transmitted unchanged in all directions, throughout the fluid, and perpendicular to the walls of the container N 18. Students may draw diagrams similar to Figure 4.31 in the student textbook. 250 This page may be reproduced for classroom use by the purchaser of this book without the written permission of the publisher.

6 TOPICS 7 8 BLM 4-26, Automobiles/Overhead Master Hints & Help: Use non-permanent coloured markers on the overhead to reinforce how an engine operates. not applicable BLM 4-27, Time Line Tells All/ Goal: Students create and evaluate a time line to show the development of the use of fluid pressure. Time lines will vary. Check for accuracy and an ability to organize information in a logical and effective way. 15. Reasons why automobiles went through design changes: style, fashion, and engine power to interest consumers improvements in fuel efficiency decrease in pollution emissions development of new technologies such as solar cells, hydrogen fuel cells, and electrically powered vehicles 16. Students may successfully argue any of these three points of view. It is more likely that both happen: society changes technology and technology changes society. The computer, for example, was initially developed to perform complex scientific calculations more quickly than humans can. The computer has gone beyond its initial purpose, however, and has changed most human functions in society. BLM 4-28, Freon /Information Handout Goal: Students learn more about the consequences of using Freon and other refrigerants. not applicable BLM 4-29, Topics 7 8 Test/ Goal: Students assess their understanding of the concepts they studied in Topics Watt 7. steamboats 2. steam 8. turbines 3. gas 9. rotate 4. coal 10. propellers 5. wood 6. piston 11. (d) 12. (c) 13. (c) 14. (c) BLM 4-30, Unit 4 Test/ Goal: Students assess their understanding of mechanical advantage and efficiency. Answers 1. (b) 8. (c) 2. (a) 9. (b) 3. (a) 10. (b) 4. (c) 11. (a) 5. (b) 12. (c) 6. (b) 13. (d) 7. (b) 14. T 15. F 16. T 17. F 18. (a) G (e) D (b) D (f ) D (c) D (g) G (d) G (h) G 19. The fulcrum could be moved closer to the load, or the length of the lever arm could be increased. This page may be reproduced for classroom use by the purchaser of this book without the written permission of the publisher. 263

7 TOPICS The fulcrum is your elbow or shoulder. The effort is applied at the hand or forearm. The load is the ball. 21. A fixed pulley changes the direction that the effort force is applied in. 22. The diameter of the pipeline could be increased, the pipeline could be straightened, the inside of the pipe could be smoothed, the force pushing the fluid could be increased, or the fluid could be heated. 23. (a) The person s heart may not be pumping with as much force, some of the blood could be leaking out of the blood vessels, the blood vessels might have expanded (dilated), or the blood could be getting thinner. (b) The person s heart could be beating with greater force, the blood vessels could be blocked or constricted, or the blood might be getting thicker. 24. Air is compressible, therefore the air would not push against the brakes with enough force to activate them unless it was first compressed. The driver of a car would have to pump the brakes many times in order to compress the air enough to activate them. Dangerous situations could arise due to the longer time it would take to get the brakes to engage. 25. Because water cannot compress, the bumper does not soften the impact unless the water slowly escapes through valves that pop open from the impact. 26. Possible answers: Heat is produced from friction between moving engine parts. Hot exhaust produced by the combustion process is lost through the exhaust system. Some energy is converted to the sound of the engine. Not all fuel is completely burned. Some fuel is lost with the exhaust. Heat is transferred to engine coolants. 27. Class Class Students first need to calculate the work done using the ramp. W = F d = 1000 N 4m = 4000 J 4000 J of work is done to push the box up the ramp into the truck. F = W d = 4000 J 1m = 4000 N It would take 4000 N of force to lift the box directly into the truck without the ramp. 264 This page may be reproduced for classroom use by the purchaser of this book without the written permission of the publisher.