. Theory of structures and strength of materials. respect to gG. Hence, A = —. or / = ^ MOMENT OF INERTIA. 13 The moment of inertia /,, of the area, with respect to aparallel axis at distance _^i from gG, is given by the equation where S = A^-^ A^-^ . . Let the new axis intersect C^g and kg in the points q and triangles qgr and 0 are similar. qr S y^~ P ~/ and, therefore, the area A of the triangle qgr _qr Sy^ Hence 2-^ 2p ly = 2pA -i-2pA = 2p{A + Ay A Note.—If p be made ^ 2 2 I=A and 5j/; = ^^,and ... T,^A{A+A). The angle \0n is also evidently a right angle. 8. Cranes.—(a), fib-c
. Theory of structures and strength of materials. respect to gG. Hence, A = —. or / = ^ MOMENT OF INERTIA. 13 The moment of inertia /,, of the area, with respect to aparallel axis at distance _^i from gG, is given by the equation where S = A^-^ A^-^ . . Let the new axis intersect C^g and kg in the points q and triangles qgr and 0 are similar. qr S y^~ P ~/ and, therefore, the area A of the triangle qgr _qr Sy^ Hence 2-^ 2p ly = 2pA -i-2pA = 2p{A + Ay A Note.—If p be made ^ 2 2 I=A and 5j/; = ^^,and ... T,^A{A+A). The angle \0n is also evidently a right angle. 8. Cranes.—(a), fib-crane.—Fig. 19 is a skeleton diagram ofan ordinary jib-crane. OA is the post fixed in the ground atO; OB is the jib ; AB is the tie. The jib, tie, and gearing aresuspended from the top of the post by a cross-head, whichadmits of a free rotation round the axis of the post. Let the crane lift a weight W. 14 THEORY OF STRUCTURES. Three forces in equilibrium meet at B\ viz., W, the tension7 in the tie, and the thrust 6 along the
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishernewyo, bookyear1896
