| John Bennett (Engineer) - 1833 - 488 pages
...give the area. Because 0,7854 and 3,1416 are the areas of circles, whose diameters are 1 and 2, and the areas of circles are proportional to the squares of their diameters. or semidiameters Again, 1 : 0,7854 :: 14 : 11, nearly, And 1 : 3,1416 :: 7 : 22, nearly. Hence the... | |
| Dionysius Lardner - Curves, Plane - 1840 - 386 pages
...the perimeters of similar polygons are in the same ratio as any two corresponding diagonals. Also as the areas of circles are proportional to the squares of their diameters, so the areas of similar polygons are proportional to the squares of their corresponding diagonals.... | |
| Jabez Hogg - Physics - 1853 - 390 pages
...effect produced as the area of the base of the small piston in d to the area of the piston g ; but as the areas of circles are proportional to the squares of their diameters, we may thus illustrate our subject : suppose a force of 50 Ibs. to represent the pressure under the... | |
| William Somerville Orr - Science - 1860 - 540 pages
...we have reckoned is about 3J horse-power. When we double the diameter of a mill, we quadruple it« power, for we quadruple its effective surface. The...sails, they are also as the squares of the diameters. ADVANTAGES OF WINDMILLS. nice; and to these we must refer such of our readers as require a more full... | |
| William John Macquorn Rankine - Engineering - 1866 - 356 pages
...following principles : — 1. The circumferences of circles are proportional to their diameters. 2. The areas of circles are proportional to the squares of their diameters. Diam. Circum. Area. Diam. Circum. Area. IOI 317-30 8012 146 458-67 16742 IO2 320-44 8171 M7 461-81... | |
| Spon E. & F.N., ltd - 1869 - 402 pages
...quadruple its power, for we quadruple its effective surface. The areas of circles are proportional to tho squares of their diameters ; and as the similar parts...matter to estimate the powers of windmills. The proper guide as to power, velocity, and construction is experience. Some of the works of Smeaton contain much... | |
| Edward Spon - Engineering - 1873 - 398 pages
...power of the mill we have reckened is about 3J horse-power. When we double the diameter of a mill, wo quadruple its power, for we quadruple its effective...diameters. It is not at all an easy matter to estimate tho powere of windmills. The proper guide as to power, velocity, and construction is experience. Some... | |
| Edward Spon, Oliver Byrne, Ernest Spon, Francis N. Spon - Engineering - 1874 - 396 pages
...double the diameter of a mill, wo quadruple its power, for we quadruple its effective eurface. Tho areas of circles are proportional to the squares of...matter to estimate the powers of windmills. The proper guide as to power, velocity, and construction is experience. Some of the works of Smeaton contain much... | |
| Popular encyclopedia - 1874 - 530 pages
...method is exemplified in the second proposition of Euclid's Twelfth Book, in which it is shown that the areas of circles are proportional to the squares of their diameters. This is proved by successively inscribing in the circles regular polygons of 4, 8, 16, &c., sides,... | |
| Robert Potts - Arithmetic - 1876 - 402 pages
...earth, supposing the diameters of the earth and moon are 8000 and 2000 miles respectively, and that the areas of circles are proportional to the squares of their diameters ? EESULTS, HINTS, ETC., FOE THE EXEECISES. I. 1. Art. 1. 2. The ratio is 7 to 22. 3. See Art. 2. 4.... | |
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