Fifth book of lessons for the use of schools . tion. It would be impossible for one child to rise per-pendicularly to the point A, or for the other to descendin a straight line to B ; they each describe arcs of theirrespective circles; and it maybe judged from the dif-ferent dimensions of the circle how much greater the. 278 FIFTH BOOK. velocity of the little child must be than that of thebigger one. Enormous weights may be raised by leversof this description, for the longer the acting part of thelever is in comparison to the resisting part, the greateris the effect produced by it; because the
Fifth book of lessons for the use of schools . tion. It would be impossible for one child to rise per-pendicularly to the point A, or for the other to descendin a straight line to B ; they each describe arcs of theirrespective circles; and it maybe judged from the dif-ferent dimensions of the circle how much greater the. 278 FIFTH BOOK. velocity of the little child must be than that of thebigger one. Enormous weights may be raised by leversof this description, for the longer the acting part of thelever is in comparison to the resisting part, the greateris the effect produced by it; because the greater is thevelocity of the power compared to that of the have all seen a heavy barrel or tun rolled overby thrusting the end of astrong stick beneath it andresting it against a log ofwood, or any other objectwhich can give it support,near the end in contactwith the barrel. The stick, in this case, is a lever, thesupport, the prop or fulcrum; and the nearer the latteris to the resistance, the more easily will the power beable to move it. There are three different kinds of levers; in thefirst, which comprehends the several levers we have de-scribed, the fulcrum is between the power and theweight. When the fulcrum is situated equally be-tween the power and the weight, as in the balance, thepower must
Size: 2371px × 1054px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1860, bookpublishermontrealjohnlovell
