A Mechanical Text-book: Or, Introduction to the Study of Mechanics and Engineering

C. Griffin, 1873 - 312 من الصفحات

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المحتويات

 Motions of Fluids 66 The Motions of Primary Moving 72 Principle of Sliding Contact 79 Teeth of SpurWheels 86 182a The Velocity of any Ply 106 Article Page 107 The General Principle 110 Resultant and Balance 125 BalanceofanySystemofParallel 131 Distributed Forces 140 Stress of Contrary Signs 146 Deviation of Principal Stresses 152
 Article Page 222 On Uniform Rotation 228 THEORY OF MACHINES 240 Algebraical Expressions 246 Work of Acceleration 252 Summation of Work of Accel 256 Reduced Inertia _ 258 Dynamometers 271 Block Brakes 277 Of the Efficiency and CounterEfficiency of Pieces 286 Efficiency of a Screw 293

مقاطع مشهورة

الصفحة 219 - The i:ni. u u. . of a machine is a fraction expressing the ratio of the useful work to the whole work performed, which is equal to the energy expended. The limit to the efficiency of a machine is unity, denoting the efficiency of a perfect machine in which no work is lost. The object of improvements in machines is to bring their efficiency as near to unity as possible.
الصفحة 107 - The tendency of a couple is to turn the body to which it is applied in the plane of the couple — that is, the plane which contains the lines of action of the two forces. (The...
الصفحة 107 - Each of the three forces is equal and opposite to the resultant of the other two; and each pair of forces are equal and opposite to the components of the third. Hence this rule serves to resolve a given force into two parallel components acting in given lines in the same plane.
الصفحة 107 - ... the ratio of the mass of a given volume of the substance to the mass of an equal volume of water, in which case it is equal to the specific gravity.
الصفحة 227 - ... the friction of the water in the pumps and pipes, the friction of the plungers, pistons, valves, and mechanism, and the resistance of the air pump and other parts of the engine. For example, the useful work of a marine steam engine in a given time is the product of the resistance opposed by the water to the motion of the ship, into the distance through which she moves : the lost work is that performed in overcoming the resistance of the water to the motion of the propeller through it, the friction...
الصفحة 4 - B sin (A — B) = sin A cos B — cos A sin B cos (A + B) = cos A cos B — sin A sin B...
الصفحة 107 - If three forces acting on a particle keep it in equilibrium, each is proportional to the sine of the angle between the other two.
الصفحة 12 - To find the area of a trapezoid. RULE. Multiply half the sum of the two parallel sides "by the perpendicular distance between them : the product will be the area.