ما يقوله الناس - كتابة مراجعة
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acceleration acting angular momentum angular velocity applied Article axes axis of rotation balance bars beam breadth called centre of gravity circular coefficient comparative motion components connected cord couple cross-section curve cylinder denote diameter direction of motion divided driving point epicycloids epitrochoids equal and opposite equation exerted expressed factor of safety figure fluid frame friction given axis given instant inertia instantaneous axis intensity intersect interval joint length line of action line of contact load machine mass mechanism moment of inertia moving pieces multiplied numbers of teeth ordinates pair of points parallel forces perpendicular distance piston pitch circle pitch surfaces polygon position pressure principles produced proportional pulley radius ratio rectangular relatively represented resistance respectively resultant right angles rigid body rotating piece screw shearing shearing stress sliding straight line stress tion traversing truss uniform unit velocity-ratio vertical weight wheel
الصفحة 241 - The Efficiency 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 129 - Then each force will be proportional to the distance between the lines of action of the other two. The direction of the middle force, C, is contrary to that of the other two forces, A and B.
الصفحة 251 - ... 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 of the mechanism, and the other resistances of the engine, and in raising the temperature of the...
الصفحة 16 - 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.
الصفحة 120 - ... 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. In its application to gases, the term
الصفحة 4 - Suppose a* =n, then x is called the logarithm of n to the böge a ; thus the logarithm of a number to a given base is the index of the power to which the base must be raised to be equal to the number. The- logarithm of n to the base a is written Iog0 n ; thus log„ii = a; expresses the same relation, as a* = n.
الصفحة 146 - P= f fpdxdy=lv^T (4.) The centre of stress is the point on the surface AA perpendicularly opposite the centre of gravity of the ideal solid. The simplest, and at the same time the commonest case of this kind is where the stress is uniformly-varying; that is, where its intensity at a given point is simply proportional to the perpendicular distance of that point from a given straight line in the plaue of tho surface A A.
الصفحة 4 - ... between 1 and 10 is obtained by moving the decimal point of the number (actual or implied) the required number of digits. The power of 10, for a number greater than 1, is positive and is one less than the number of digits before the decimal point in the original number. The power of 10, for a number less than 1, is negative and is one more than the number of zeros immediately following the decimal point in the original number. Hence...
الصفحة 223 - The Radius of Gyration of a body about a given axis is that length whose square is the mean of all the squares of the distances of the indefinitely small equal particles of the body from the axis, and is found by dividing the moment of inertia by the mass...