MechanicsLongman, Rees, Orme, Brown, and Green, and John Taylor, 1830 - 342 Seiten |
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acting angle angular velocity applied atoms attraction axle ball called carriage cause centre of gravity centre of oscillation centrifugal force component compression cord crystallisation curve cycloid cylinder descend diameter diminished DIONYSIUS LARDNER distance earth effect equal equi equilibrium equivalent explained falling freely feet figure final velocity force of gravity friction fulcrum greater Hence impact inches inclined plane increase inertia length lever line of direction liquid machine magnet magnitude manner mass matter mechanical molecule moment of inertia move necessary observed ounces parallel parallelogram of forces particles pendulum perpendicular phenomena pinion placed point of suspension pores porosity position pressure principal axis principle produce proportion pular language pulley quantity of motion radius radius of gyration rection resistance rest revolve rope round screw side single force solid body space substances suppose surface suspended sustain thread tion uniform vessel vibration volume weight wheel wire
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Seite 54 - ... 64 feet per second ; and towards the end of the fall, it would be about 120 feet per second. It is evident that this great degree of rapidity would be a serious impediment to accurate observation, even though we should be able to command the requisite height. It occurred to Mr. George Attwood, a mathematician...
Seite 5 - When air is violently compressed, it becomes so hot as to ignite cotton and other substances. An ingenious instrument for producing a light for domestic uses has been constructed, consisting of a small cylinder, in which a solid piston moves air-tight : a little tinder, or dry sponge, is attached to the bottom of the piston, which is then violently forced into the cylinder : the air between the bottom of the cylinder and the piston becomes intensely compressed, and evolves so much heat as to light...
Seite 121 - ... indentures of each wheel fall between the corresponding ones of that in which it works, and ensure the action BO long as the strain is not so great as to fracture the tooth.
Seite 83 - ... position must be regulated by the centre of gravity of his body and the load taken together. If he bore the load on his back, the line of direction would pass beyond his heels, and he would fall backwards. To bring the centre of gravity over his feet he accordingly leans forward, fig.
Seite 217 - ... the distance from the point of suspension to the centre of oscillation must remain the same.
Seite 154 - In many cases, the utility of the wedge depends on that which is entirely omitted in its theory, viz., the friction which arises between its surface and the substance which it divides. This is the case when pins, bolts, or nails, are used for binding the parts of structures together ; in which case, were it not for the friction, they would recoil from their places, and fail to produce the desired effect. Even when the wedge is used as a mechanical engine, the presence of friction is absolutely indispensable...
Seite 19 - Every body must persevere in its state of rest, or of uniform motion in a straight line, unless it be compelled to change that state by forces impressed upon it.
Seite 61 - The consideration of centrifugal force proves, that if a body be observed to move in a curvilinear path, some efficient cause must exist which prevents it from flying off, and which compels it to revolve round the center. Thus the bodies of the solar system are constantly impelled or drawn towards the sun by a force which we denominate gravity.
Seite 22 - ... and is usually expressed thus : " If two forces be represented in quantity and direction by the sides of a parallelogram, an equivalent force will be represented in quantity and direction by its •diagonal.
Seite iv - Animalcules have been discovered, whose magnitude is such, that a million of them does not exceed the bulk of a grain of sand ; and yet each of these creatures is composed of members as curiously organized as those of the largest species ; they have life and spontaneous motion, and are endued with sense and instinct.