Greenwood press
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book-20600
RATIO
105 online sources for further exploration Consumer price index (CPI) The P/E ratio and other stock ratios are discussed at the Motley Fool page Musical scales FAA instructions on making a scale drawing of an F-16 Compute gear ratios for a bicycle U. S. Census Bureau QuickFacts on States (Rates and Ratios) Body-mass calculator Cooking by numbers Density lab How to compute baseball standings Scale models Screen ratios Tuning in ▲ ▼ ▲ 106 RATIO REFLECTIONS A reflection is a transformation that produces an image of equal size by flip- ping an object over a line. For example, you will see a reflection of yourself when you look in the mirror. Your size in the mirror will be the same as your actual size, but all of your features will be reversed. So if your hair is parted to the left, it will appear to be parted to the right in a reflection. Using two mirrors can create double reflections, allowing someone such as a hair stylist to show you the back of your head after a haircut while you look straight ahead. Reflections of objects are naturally visible in water. If you walk up to a pond on a still, sunny day, you will see an image of yourself on the surface of the water. In the picture below, buildings and boats on a Holland canal are reflected in the surface of the canal. The reflection is so good that when you turn the pic- ture upside down, it looks almost the same. Reflections are sometimes used to create illusions or expand the size of an object. Many restaurants have large mirrors on one wall so that the room will appear twice as large. In an amusement park, a house of mirrors creates multiple images of anyone walking through, making it difficult to determine the correct pathway to the exit. Another example of using reflections to replicate an object is to create designs with a kaleidoscope. A kaleidoscope is a cylindrical toy that cre- ates colorful patterns by using tiny objects situated at its base and in between two intersecting mirrors. The reflections at the base repeat themselves as a function of the angle n between the mirrors. Since there are 360 degrees in a circle, then there will be 360 n repetitions of the object caused by reflections. Each time the kaleidoscope rotates, the tiny objects inside it move around and consequently change the symmetrical pattern one sees when looking through the cylinder. Download 1.81 Mb. Do'stlaringiz bilan baham: |
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