Greenwood press
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book-20600
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112
ROTATIONS Tessellation of lizard tiles based on rotations for an outdoor patio. The gears of a bicycle rotate and latch onto the chain to help propel the bicycle forward when force is applied to the pedals. rate of approximately 1,037 miles per hour, because these objects travel 2 2π(3,963) miles in twenty-four hours. The angular rate of objects in circular motion is the circular distance divided by the time to travel that distance. If a person is stand- ing away from the equator, then his or her angular rate is 2π•3963•cos θ 24 , where θ is the latitudinal angle of the city. For example, if a person is standing at 60°N latitude, then he or she will only be half as far from the earth’s axis of rotation, because cos 60° is one-half. Then this person will only be moving half as fast around the earth. People actually do not feel like they are moving faster at dif- ferent parts of the world because everything else is moving at the same rate. You feel differences in motion when something else is moving faster or slower than your motion. Rocket launches take advantage of the earth’s rotational velocity. The launch- ed aircraft takes off towards the east—the same direction as the rotation of the earth—giving it an extra boost once it is airborne. Also, launches in the United States are at Cape Canaveral, Florida, which is closer to the equator than most other cities in the country. Since it is farther from the earth’s axis of rotation than many other U.S. cities, the earth’s rotation will be more supportive at that loca- tion by giving it almost the best possible additional speed as it leaves the earth’s atmosphere. online sources for further exploration Applications of rotations Bicycle gears Image rotation Mathematical art of M. C. Escher Relative motion—rotation and the motion of the moon Rotations on a sphere Download 1.81 Mb. Do'stlaringiz bilan baham: 
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