. A text book of elementary mechanics, for the use of colleges and schools. erting a force of 800 lbs. walks in a circle havinga diameter of 18 feet and turns, by means of a lever-arm, a verti-cal post about which a rope is wound: If the diameter of the postis 8 inches, what resistance (, that of a building which is beingmoved) can the horse overcome ? 3. Four men, each exerting a force of 60 lbs. acting on separatelever-arms, 4 feet long, turn a capstan: the radius of the circleabout which the rope is wound is 6 inches: What is the pull feltupon the anchor? 4. A weight of 500 lbs. hangs b
. A text book of elementary mechanics, for the use of colleges and schools. erting a force of 800 lbs. walks in a circle havinga diameter of 18 feet and turns, by means of a lever-arm, a verti-cal post about which a rope is wound: If the diameter of the postis 8 inches, what resistance (, that of a building which is beingmoved) can the horse overcome ? 3. Four men, each exerting a force of 60 lbs. acting on separatelever-arms, 4 feet long, turn a capstan: the radius of the circleabout which the rope is wound is 6 inches: What is the pull feltupon the anchor? 4. A weight of 500 lbs. hangs by a rope 1 inch in thickness;r — 8 in., and B = 4 feet; the power acts on a lever-arm withouta rope: What is P? 5. A power of 12 lbs. balances a weight of 200 lbs.; the radiusof the axle is 3 inches: What is the diameter of the wheel ? 6. In Fig. 148, R = 18 in., and the weight of 250 lbs. rises 2 feetwhile the power makes 5 revolutions: What is P? III. Toothed Wheels. 209. A Toothed Wheel is a circular disc providedwith teeth on the circumference; such a wheel turning. Fig. 152. on one axis interlocks with a second turning on anotheraxis (Fig. 152), and in this way the force applied at 210.] TOOTHED WHEELS. 221 the first is communicated to the second. There maybe a mechanical advantage with a corresponding loss ofspeed, or a gain in velocity and a consequent mechani-cal disadvantage. When the wheels are small, the teeth are nearly rect-angular in form. When the wheels are very large andgreat force is employed, the shape of the teeth is amatter of essential importance, in order that the loss ofpower arising from their mutual friction and resistance
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectmechanics, bookyear18
