Safety Note features identify safe practices for conducting procedures that might result in injury if done improperly. 464 Technology: Engineering Our World Copyright Goodheart-Willcox Co., Inc. Think about the ways that electrical energy affects our homes, transportation, offi ces, and factories. Electric motors run food mixers, blowers, pumps, dishwashers, washing machines, and many other appliances. Motors power subway trains and golf carts. Cars have on average 100 microprocessors that communicate with one another to ensure safety, comfort, and fuel economy. Electricity operates the lights in movie theaters and sports stadiums. In your home, electricity powers alarm systems, smartphones, and oxygen tanks. Most large supplies of electricity come from generating stations and grid systems to homes and businesses. However, there are many ways to generate small amounts of electricity, including friction, chemical reactions, light, heat, and pressure (Figure 16-1). Prior to the late 1800s, electricity was a curiosity. Electrical appliances were almost unknown. This situation changed in 1879 when Thomas Edison invented a reliable light bulb that lasted a long time. People started switching from gaslights to electric lighting. Today, factories use electricity and electrical circuits to start and stop machines automatically. Electricity controls assembly lines and robots. Whole factories can be run electrically. A few people working at computers can control machines, lights, assembly lines, packaging, and loading of products. Indeed, it is hard to imagine what we would do without electricity. Safety Note: Remember that every time you work with electricity, you must think about the hazards and risks involved. • Water and electricity are a dangerous combination. Keep all electrical devices away from sinks, swimming pools, and bodies of water. • Do not fly kites near power lines. • If a ball or other object gets stuck in a tree near a power line, do not try to get it down. • Use only 1.5 V cells or 9 V batteries to power your experiments in this course. Think Green Think Green With electronics technology improving every day, our electronic devices become “old” quickly. New, improved products are constantly being introduced. When we replace our existing electronics with new versions, what happens to the old ones? How responsibly do we act? The first question to ask yourself is whether you really need the latest and greatest products. Will they really work better than your existing electronics, or are they just a status symbol? When you do decide to upgrade your electronic devices, the next question is what to do with the old ones. If the devices are in working condition, one good solution is to give them to charity. Many organizations collect electronics for use in schools and community programs. A number of national organizations have electronics recycling and reuse programs. Your community may also have donation and recycling opportunities. The next time you replace an electronic device, research opportunities for donating or recycling your old devices. You may be able to help people in need, as well as do your part to help the environment. Recycling Electronic Devices Think Green notes highlight key items related to sustainability, energy efficiency, and environmental issues. Copyright Goodheart-Willcox Co., Inc. Chapter 5 Sketching and Drawing Techniques 119 CHAPTER 5 Review and Assessment Summary • Sketching allows a designer to easily and quickly record and share ideas. • Perspective sketches provide the most realistic representation of an object. • Orthographic projection shows the true shape of an object. • Orthographic projections provide all dimensions required to manufacture an object. • Computer-aided design (CAD) has now replaced manual drafting. • A CAD system consists of an input device, a processor, and an output device. • A CAD system can be linked to a computer-aided manufacturing system. Check Your Engineering IQ Now that you have finished this chapter, assess what you learned by taking the chapter posttest. www.g-wlearning.com/technologyeducation/ Review Questions Answer the following questions using the information provided in this chapter. 1. True or False? Perspective sketching provides a realistic representation of an object. 2. True or False? A sketch describes the shape of an object exactly. 3. True or False? Sketches allow the designer to develop and record ideas. 4. True or False? Three orthographic views are required to provide complete information about an object. 5. Which views of an object does a complete set of orthographic projections show? A. Front, left side, and bottom. B. Top and right side. C. Front, top, and right side. D. Front, top, and bottom. 6. Which dimensions will be shown on a complete set of orthographic projections? A. Overall dimensions only B. Detail dimensions only C. Overall dimension with some detail dimensions D. Overall and detail dimensions 7. True or False? In an orthographic projection, a line of alternating long and short thin dashes shows the center of a hole. 8. True or False? An architect’s drawing of a bridge is an example of a scale drawing. 9. What scale is a drawing that is twice full size? A. 1:2 B. 1:20 C. 2:1 D. 20:1 10. What devices are required for a computer-aided design (CAD) system?processorand A. Input device, output device, B. Input device, processor, and laptop computer C. Processor, output device, and tablet D. Processor, computer, and printer Summary feature provides an additional review tool for you and reinforces key learning objectives. Review Questions allow you to demonstrate knowledge, identification, and comprehension of chapter material. Apply Your Knowledge activities allow you to apply the skills and knowledge you have learned in the chapter. Critical Thinking questions develop higher-order thinking, problem solving, personal, and workplace skills. Copyright Goodheart-Willcox Co., Inc. Chapter 5 Sketching and Drawing Techniques 121 3. Create a collage to illustrate the many types of sketches and drawings used to convey information. A. Collect at least 20 sketches and drawings. Sources will include magazines, advertising materials, and prints from the Internet. B. Cut off excess paper from around the edges of each illustration to make them interesting shapes. C. Get a sheet of cardboard or foam board approximately 24″ × 36″ (60 cm × 90 cm). D. Using color pencils, markers, or paint, add a title that will convey to a viewer the purpose of the collage. E. Paste your illustrations to the board in a pattern that will intrigue viewers. F. In the spaces between illustrations, name the type of sketch or drawing, and write notes to explain its purpose, advantages, and disadvantages. Communicating about Engineering 1. Working in groups of three students, create fl ash cards for the key terms in this chapter. Divide the key terms between yourselves and write each key term on a fl ash card. On the back of the card, write the pronunciation and a brief defi nition. Use your textbook and a dictionary for guidance. Then take turns quizzing one another on the pronunciations and defi nitions of the key terms. 2. As you read the chapter, record any questions that come to mind. Indicate where the answer to each question can be found: within the text, by asking your teacher, in another book, on the Internet, or by refl ecting on your own knowledge and experiences. Pursue the answers to your questions. STEM Applications 1. Technology. Select a category of product design that particularly interests you. This might be architecture, fashion, vehicles, furniture, or jewelry. It is important that you want to learn more about design and designers of products in this category. Use your preferred web browser to fi nd illustrations of contemporary designs in the category. Print one or two for future reference. Use these illustrations as a starting point to sketch ideas from which to develop your own ideas for new products in the same category. 2. Engineering. Using the Internet, type in “famous architects of the twenty-fi rst century.” Browse through results and identify the work of an architect whose buildings you fi nd intriguing. Select one example of his or her work. Print as many images of the building as are available. Make your own sketches of the building. Next, use either drawing instruments or CAD software to produce a set of orthographic drawings for the building. If dimensions are not available, try to preserve the proportions created by the architect. 3. Math. Select an object you use or see every day. Using a tape measure or rule, measure the dimensions of the object carefully. Create an orthographic projection of the object using manual drawing or CAD techniques. If the object is too large or small to be shown fully and clearly on one sheet of paper, create a scale drawing. Include dimensions. Communicating about Engineering activities are designed to improve and develop language skills, such as reading, speaking, and listening. STEM Applications encourage application of concepts to real-life situations, developing skills related to chapter content. c c Critical Thinking 120 Technology: Engineering Our World Copyright Goodheart-Willcox Co., Inc. Apply Your Knowledge 1. Using the techniques you learned in the chapter, produce the following sketches and views. A. On isometric graph paper, sketch the uppercase letters E and T. Make the height of each letter 10 squares, with the horizontal arms in proportion. B. On plain white paper, make an isometric sketch of the letters L and H. Make the height of each letter 10 squares, with the horizontal arms in proportion. C. On plain white paper, make a perspective sketch of one simple object in your home. D. Using graph paper, draw three orthographic views of one simple object in your home. 2. Research one career related to the information you have studied in this chapter. Write a report that contains the following: A. The career you selected. B. The educational requirements for this career. C. What someone with this career does on a daily basis. D. The possibilities for promotion to a higher level. E. The earning potential for someone with this career. Look for this information on the Internet or in a library. If possible, interview a person who already works in this career to provide information on the five points. Finally, describe why you might or might not be interested in pursuing this career when you finish school. Critical Thinking 1. This task will illustrate the essential role that sketches play in the work of a designer. Imagine that you have been asked to design a new piece of garden furniture. Complete the following steps: A. Decide what sort of furniture it will be (table, chair, stool, etc.). B. Imagine what this piece might look like, including the overall shape and color. C. Plan in your mind some of the details, including the shapes of individual parts and how parts might fi t together. D. Describe your new product to a friend, using only words. E. Ask your friend to make some sketches of how they see your imagined product. Do not look at these sketches. F. While your friend is making sketches, produce sketches of the ideas in your head. Include as much detail as possible. G. Compare your sketches with those made by your friend. In what ways are they similar? In what ways are they different? What do you conclude about sketching as an essential skill for the designer? 2. A friend has asked you to make the coffee table shown in the following photograph. The only dimensions given to you are that the top is to be 50″ × 21″ × 1 1/4″ (125 cm × 50 cm × 3 cm), and the height 16″ (40 cm). All other dimensions, which should be in proportion to the top and height, are to be calculated by you. Your task includes the following: ParvinMaharramov A. Calculate the dimensions of the legs. B. Plan the position of the legs relative to the size of the top. C. Make a perspective sketch of the table. D. Make dimensioned sketches of the various parts of the table. E. Make a set of orthographic projections of the table using the dimensions from your sketches.