Georgia Performance Standards Framework for Physical Science 8 th GRADE. Unit: Fast and Furious Forces General Task Life is Easy with Simple Machines

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1 Subject Area: Physical Science Grade: 8 Unit: Fast and Furious Forces General Task Life is Easy with Simple Machines S8P3. Students will investigate relationship between force, mass, and the motion of objects. c. Demonstrate the effect of simple machines (lever, inclined plane, pulley, wedge, screw, wheel and axle) on work. S8CS1. Students will explore the importance of curiosity, honesty, openness, and skepticism in science and will exhibit these traits in their own efforts to understand how the world works. a. Understand the importance of and keep honest, clear, and accurate records in science. b. Understand that hypotheses can be valuable even if they turn out not to be completely accurate. S8CS2. Students will use standard safety practices for all classroom laboratory and field investigations. a. Follow correct procedures for use of scientific apparatus. b. Demonstrate appropriate techniques in all laboratory situations. c. Follow correct protocol for identifying and reporting safety problems and violations. S8CS3. Students will have the computation and estimation skills necessary for analyzing data and following scientific explanations. a. Analyze scientific data by using, interpreting, and comparing numbers in several equivalent forms, such as integers, fractions, decimals, and percents. f. Use ratios and proportions, including constant rates, in appropriate problems. S8CS4. Students will use tools and instruments for observing, measuring, and manipulating equipment and materials in scientific activities utilizing safe laboratory procedures. b. Use appropriate tools and units for measuring objects and/or substances. c. Learn and use standard safety practices when conducting scientific investigations. Gifted: S8CS6. Students will communicate scientific ideas and activities clearly. c. Write for scientific purposes incorporating information from a circle, bar, or line graph, data, tables, diagrams, and symbols. d. Organize scientific information in appropriate tables, charts, and graphs, and identify relationships they reveal. July 2008 Page 1 of 9

2 Gifted: S8CS9. Students will understand the features of the process of scientific inquiry. Students will apply the following to inquiry learning practices: b. Scientific investigations usually involve collecting evidence, reasoning, devising hypotheses, and formulating explanations to make sense of collected evidence. e. Accurate record keeping, data sharing, and replication of results are essential for maintaining an investigator s credibility with other scientists and society. f. Scientists use technology and mathematics to enhance the process of scientific inquiry. Enduring Understanding: Simple machines are tools that help us do work. Simple machines make work easier for us changing the amount of force (pushing or pulling) needed to do certain kinds of work. Essential Questions: How do simple machines make our lives easier? ADMINISTRATION PROCEDURES Pre-Assessment: To assess how familiar your students are with simple machines, go to the following link and let students take turns predicting whether the list of common objects are simple machines and, if so, predict the type of machine. Answers and pictures are provided to make this an interesting and informative introduction to simple machines. July 2008 Page 2 of 9

3 Outcome / Performance Expectations: General Teacher Instructions: In this exploration students will identify different types of simple machines, compare their similarities and differences and explain how simple machines are designed to help us to work. While students have used simple machines hundreds of times by the time they reach middle school, they are often unaware of what they are or how they function. As a starting point, we can describe simple machines as tools that we use to help us do work. While students usually think that work means to exert oneself by doing mental or physical activity, the term work in science means to exert a force on an object in order to move it. Most machines function by changing the amount of force (pushing or pulling) needed to do certain kinds of work. Since human bodies are designed to more to move than they are to push or pull, machines are usually designed to take a large movement with a little force and convert it into a short movement with a stronger force. For example, a bottle opener allows us to convert a large movement up with a little force from our arm, to a short movement down with a greater force on the cap (enough to open it). There are several types of simple machines that each helps us in different ways to make work easier. In this exploration, we will begin by asking students to do some basic research on the six common types of simple machines. Using their textbook, notes, resource books and the Internet, they must describe and draw an example of each the six types of simple machines. a. lever a rigid bar that pivots about a fixed point (fulcrum) b. pulley a wheel with a groove and a rope that is usually used to help lift an object by changing the direction of a pull (force) c. inclined plane a slanted surface that is used to help raise an object d. wheel and axel - a wheel is locked to a central rod (called the axel) so that when one turns the other turns a longer motion at the outside of the wheel is converted into a shorter more powerful force at the axel, example: steering wheel also works in reverse, a short powerful force at the axel will move the wheels outer edge a long distance but without much force, example, pedaling a bike July 2008 Page 3 of 9

4 Materials Needed: Task with Student Directions: Resources: e. wedge an inclined plane that moves usually a wedge is a combination of two inclined planes wedges are use to split, cut, or divide other objects an axe, knife, and our canine teeth are examples of wedges f. screw a rod with a thread wrapped around it to form a spiral it is used as a fastener to hold objects together Materials: Choose any ten of the following simple machines for your secret machines: Screw driver, chisel, corkscrew, can opener, rope and pulley, faucet handle, tape dispenser, steering wheel, plastic knife, hammer, pliers, broom, doorknob, plastic sandbox shovel. Paper bags or small boxes Inexpensive simple machines like these can be purchased at local dollar stores. As an alternative, you can use laminated pictures of simple machines for your Secret Machines. See attachment at the end of this document Great Simple Machine Animations Nice summary of simple machines with on-line activities More great links to simple machine sites Homework / Extension: Instructional Task Accommodations for ELL Students: As a homework/extension for this activity, students can design their own tool that uses at least one simple machine. The tool should be designed to make a simple everyday task easier for them to accomplish in other words, in should make work easier. Students can present their designs to the class and should show how their design uses at least one simple machine to make work easier. Their presentation should include a PowerPoint, brochure, podcast, or some other creative format. Pair with more advanced native language speaking partner ( allow for translation in native language for comprehension) as needed Provide bilingual support using word to word translation such as dictionaries, and glossaries Provide native language text books and support material whenever possible July 2008 Page 4 of 9

5 Instructional Task Accommodations for Students with Specific Disabilities: Review and Implement IEP accommodations for specific student needs Other accommodations may include: Allow extended time for written tasks Post all new vocabulary on a word wall Give instructions clearly and restate them in other ways so all students understand Give instructions clearly and restate them in other ways so all students understand. Provide students with written step by step instructions for the lab procedure; keep language simple Instructional Task Accommodations for Gifted Students: Students can research how we can combine several basic simple machines in order to construct a complex machine. For example, a bicycle is a complex machine that uses several simple machines to accomplish its function of moving the rider down the street. July 2008 Page 5 of 9

6 Life is Easier with Simple Machines In this exploration you will investigate how simple machines are designed to make our lives easier. Simple machines are tools that help us do work. Simple machines make work easier for us changing the amount of force (pushing or pulling) needed to do certain kinds of work. Since human bodies are designed to more to move than they are to push or pull, most machines are designed to take a large movement with a little force and convert it into a short movement with a stronger force. For example, we could use a pliers like the one above to convert a large movement with a little force from our hand, to a short movement down with a greater force on the nut (enough to break it open). We will begin this activity by completing the following table in which you should describe and draw an example of each the six types of simple machines. You may use your books, the internet, or other sources to complete it. July 2008 Page 6 of 9

7 Part 1: Types of Simple Machines Lever Description Diagram Inclined Plane Wedge Wheel and axle Pulley Screw Part 2: Now it is time for you to apply what you have just learned about machines in order to help them identify a series of Secret Machines. Each of the Secret Machines is a common household item that you probably will recognize. For each Secret Machine, your job is to remove it from the bag, determine its common name, describe what you think it does, and then identify as one of the six types of simple machines. You will have 3 minutes at each station to complete your observations and analysis. At the end of the 3 minutes, you will rotate to the next station until each station is complete. July 2008 Page 7 of 9

8 Secret Machine Common Name What you think it does? Type of Simple Machine July 2008 Page 8 of 9

9 Questions: 1. After discussing your ideas about work as a class, explain what scientists mean by the term work? 2. What is the advantage of using a simple machine? 3. Of the six different simple machines we learned about, which one do you think is the most useful or valuable to people? Explain your answer. 4. Choose one of the Secret Simple Machines that you investigated and, in your words, explain how simple machines help us to do work. July 2008 Page 9 of 9