. Natural philosophy. including statics, hydrostatics, pneumatics, dynamics, hydrodynamics, the general theory of undulations, the science of sound, the mechanical theory of music, etc. : designed for the use of normal and grammar schools, and the higher classes in common schools . 3-1416 471240 4005540rK) Then W = d ^y^ ^1-31 E.^ERCISE. 103. What power will exert a pressure of 100000 lbs. by meansof a differential screw in which the power lever is 100 incheslong, the pitch of the outer screw -j^y of au inch, and that ofthe inner screw -^V of an inch ? Ans. -102 or about -,^7 of a lb. 104. Wha
. Natural philosophy. including statics, hydrostatics, pneumatics, dynamics, hydrodynamics, the general theory of undulations, the science of sound, the mechanical theory of music, etc. : designed for the use of normal and grammar schools, and the higher classes in common schools . 3-1416 471240 4005540rK) Then W = d ^y^ ^1-31 E.^ERCISE. 103. What power will exert a pressure of 100000 lbs. by meansof a differential screw in which the power lever is 100 incheslong, the pitch of the outer screw -j^y of au inch, and that ofthe inner screw -^V of an inch ? Ans. -102 or about -,^7 of a lb. 104. What pressure will be exerted by a power of 20 lbs. actingon a differential screw in which the power lever is 50 incheslong, the pitch of the exterior screw j^i- ofau inch, and thatof the inner screw i of an inch? Am. 345576 lbs. 105. What power will give a pressure of 00000 lbs. by meansof a differential screw in which the power lever is GO inches,the pitch of the outer screw -J^,, and that of the inner screwfs of an inch? Ans. 2-G52 lbs. THE EXDLESS The Endless Screw, Fig. Fig. 15. 15, is an instrument formed by ^;iBmMMMB^icombining the screw with thewheel and axle. The teeth of thewheel are set obliquely so as toact as much as possible on thethreads of the 46 THE ENDLESS SCREW. [Aets. 132,133. 132. Ill Fig. 15 eacli revolution of the liandle makesthe wheel revolve only through the space of one cog ;hence if the whole has 24 cogs, the winch must revolve24 times in order to make the wheel revolve once. Itfollov^s tJiaf ill the endless or perpetual screw the con-ditions of equilibrium arc that the pov:er is to the weightas the radius of the axle is to the product of the numberof teeth in the wheel multiplied by the length of the winch ;i. e., the radius of the circle described by the power. 133. For the endless screiv let P = power^ W =i weight, 1 = lengthofxcinch or handle^ t = number of teeth in the wheel, ajid r ?=. radiusof axle. Wx r PxlXt Then F : W :: r :
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectphysics, bookyear1867
