Mechanics of engineeringComprising statics and dynamics of solids: and the mechanics of the materials of constructions, or strength and elasticity of beams, columns, arches, shafts, etc . = units,7r-measure, , ( ~- 2^r) = revolutions, while Px hassunk through s = \6atf = ft., vertically. The tension in the cord, from (2), isp = 48(1 - X i -*- g) = 48(1 - ) = lbs. The pressures at the bearings will be as follows, at any in-stant: from (4) and (8), Xx and X2 must individually be zero;from (6) Z2 = Q = Vy = 90 lbs.; while from (5) and (7), Yx= — lbs.,
Mechanics of engineeringComprising statics and dynamics of solids: and the mechanics of the materials of constructions, or strength and elasticity of beams, columns, arches, shafts, etc . = units,7r-measure, , ( ~- 2^r) = revolutions, while Px hassunk through s = \6atf = ft., vertically. The tension in the cord, from (2), isp = 48(1 - X i -*- g) = 48(1 - ) = lbs. The pressures at the bearings will be as follows, at any in-stant: from (4) and (8), Xx and X2 must individually be zero;from (6) Z2 = Q = Vy = 90 lbs.; while from (5) and (7), Yx= — lbs., and Y* = — lbs., and should point in adirection opposite to that in which they were assumed in (see last lines of § 39). 116. Torsion Balance. A Variably Accel. Rotary Motion. Axis Fixed.—A homogeneous solid having an axis of symmetry is suspended by an elastic prism,or filament (whose mass may beneglected), so that the latter i&vertical and coincident with theaxis of symmetry, and is not onlysupported, but prevented fromturning at its upper 130. If the solid is turned about its axis away from its position of rest and set free, the torsional. DYNAMICS OF A RIGID BODY. 117 -elasticity of the rod or filament, which is fixed in the solid,causes an oscillatory rotary motion. Required the duration ofan oscillation. Fig. 130. Take the axis Y at the middle of the oscillation (the originalposition of rest). Reckon the time from the instant of passingthis position. Let the initial angular velocity = go0. As themotion progresses go diminishes, , 6 is negative. To consider the body free, conceive the rod cut close to thebody (in which it is firmly inserted), and in the section thusexposed put in the vertical tension P, and also the horizontalforces forming a couple to which at any instant the twistingaction (of the portion of rod removed upon the part left in thefree body) is known to be due. Call the moment of this coupleQb (known as the moment of
Size: 1907px × 1310px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectenginee, bookyear1888
