Transcription

1 Name: Date: D. Thomassen 2007 Levers, Gears, and PUlleys by Alma Ransford answer key Colorado Model Content Standard #2: Physical Science: Students know and understand common properties, forms, and changes in matter and energy. Directions: After reading this text, complete the following organizer parts. Remember to reread any part of the text that confused you. You are a great reader. Part I: Vocabulary Preinstruction: Vocabulary Word: calipers cranks interconnected intricate oscillatory spur gear Definition: parts of a bicycle s brake system that squeeze the wheels parts of a bicycle that connect the pedals to the front gears having parts that are joined together of complicated or very elaborate nature having a back-and-forth motion a gear with straight teeth sticking out from its edges 1. visual ( Follow along with your eyes as I spell it out loud ) 2. auditory (Hear the parts /p/ /ea/ /ch/) 3. kinesthetic (trace with eyes, write it on the table, hand, etc.) 4. phonics (break the word apart) discuss prefixes, suffixes, roots, compounds, phonograms, double vowels, silent e. 5. meaning (give the definition and/or an example) 6. give an example. I will be working with this group, meanwhile, this group will be at computers

2 Part II: Comprehension 1. What is the formula for work? In your own words, explain what you think this formula means. Work=force x distance. Any logical inference will do show an example of pushing an object a certain distance and show them that that takes work. 2. In the text it says, Inventors are always trying to find ways to make tasks and work easier. Design a machine that might make one of the jobs you are required to do easier. Be sure to label the parts of your machine. 3. Use the text to help you define the word machine. List three examples of a machine. A machine is any device that helps people do work. Wheelbarrow, scissors, baseball bat, shovel, and much more.

3 Questions to Consider: Simple Machines: How does this machine work? How does this machine reduce the amount of work you have to do? Give one or two examples of this machine. Inclined Plane It works like a ramp to that you do not have to dead lift heavy objects. By pushing an object up a ramp, you increase your distance but reduce your work. ramp, screw, wedge Levers It works by pushing on the opposite end of the load and by positioning the fulcrum correctly. When the fulcrum is close to the object that is to be lifted, the work becomes easier screwdriver, nutcracker, chopsticks, 2x4 board (use this as example in a class) Wheel and Axle By applying small amounts of pressure, the wheels begin to spin. When you pedal the bike your foot moves in a large circle, but the axle turns in a small circle. The axle turns with much more force than the pedal turns, but the pedal moves a much longer distance. bicycle, gears, tires, pedals, handlebars Pulleys A load is attached to one end of the rope, and effort force is applied to the other end. The pulley allows you to spread the weigh out over a longer distance to lift. crane 4. The authors believe that compound machine must have existed 2,500 years ago because cave drawings revealed different pictures of machines. objects were found that were so intricate that they could not have been made by hand. numerous scientific journals revealed sketches of machines. many of the machines still exist today. 5. What was the author s purpose in writing this book? The author wanted to entertain the reader with stories about ancient machines. The author wanted to persuade the reader to use machines. The author wanted to inform the reader about the different types of machines that exist. The author wanted to inform the reader about bicycle safety.

4 Part III: Compare and Contrast Analogies: We use analogies to identify relationships between pairs of concepts (Marzano 2001). Examples: happy:sad::big:small ("happy is to sad as big is to small") Directions: Complete these analogies that were created from the text you just read. inclined plane:ramp::levers:pliers support:fulcrum::work:force x distance fixed:movable::squeeze:release intricate:simple::full:empty screw:inclined plane::crane:pulley bi:2::tri:3 Part IV: Fluency Practice: Follow the four-step fluency practice steps: 1. Read the following excerpt from the text to your teacher. You must focus on pronouncing each word correctly. Take your time and do a great job. Your teacher will then discuss any words that may have been difficult for you. Record your time in the space provided. 2. Read the following excerpt from the text to yourself. Record your second time in the space provided. Ask yourself: Do I understand what happened in the text? 3. Read the following excerpt from the text to a classmate. Record your third time in the space provided. Ask yourself: Is my fluency speed improving? 4. Read the following excerpt from the text to a parent or sibling. Have them sign in the space provided. This will let your teacher know that you completed the fourth step of your fluency practice. Fluency Goal: Your fluency goal for this excerpt is to cut your time in half from your first reading to your fourth reading. If you do not complete your goal, you need to continue reading this excerpt until you accomplish that goal. When you have reached your goal, write down the main idea (one sentence) of your excerpt on the line provided. You will read this excerpt to your teacher one final time. Simple machines are very common. Most of them have one movable part. All of them fall into one of the following groups: lever, inclined plane, wedge, screw, wheel and axle, or pulley. Within each of these groups, there are many types. Pulleys can be either fixed or movable. Levers fall into three categories based on the position and role of the fulcrum, load, and effort force. Machines change the distance over which a force is exerted and the effort force needed to do work. Another important thing for inventors of machines to consider is friction. Inventors try to reduce the amount of energy lost by reducing friction between the moving parts of the machine they are designing.

5 117 words First Read: Second Read: Third Read: Fourth Read: Parent Signature: Main Idea: