The Principles of Physics |
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acceleration amperes angle armature axis ball battery body Bunsen cells called cause cell center of mass centimeter centroid circuit coil color component conductor convex lens density direction disk distance dynamo dynes earth electricity electroscope energy equal equilibrium exerted Experiment feet foot-pounds force acting galvanometer gases given glass gram gravitation greater heat hence hight inches increase kilogram kinetic energy length lens light lines of force liquid machine magnetic mass matter measure mechanical advantage mercury mirror molecules momentum motion move needle ohms parallel particle pass pendulum placed plane plate polarization pole position potential pounds pressure produced quantity radiation rays reflected refraction represent resistance resultant rotation SECTION sound sound-waves specific density spectrum straight line string substance surface temperature tion traversed tube unit vapor velocity vertical vessel vibrations waves weight wire zinc
Popular passages
Page 497 - Ampere, which is one-tenth of the unit of current of the CGS system of electromagnetic units and which is represented sufficiently well for practical use by the unvarying current which, when passed through a solution of nitrate of silver in water, in accordance with a certain specification, deposits silver at the rate of 0.001118 of a gramme per second.
Page 358 - See f/stop. focal length When the lens is focused on infinity, it is the distance from the optical center of the lens to the focal plane. focal plane The plane on which a lens forms a sharp image. Also, it may be the film plane or sensor plane.
Page 158 - But it indirectly feels the pressure of the air on the surface of the water in the open vessel, and it is this pressure that sustains the water in the jar. But the rubber bottom of the jar B yields somewhat to the downward pressure of the air, and is forced inward.
Page 302 - The total energy of any body or system of bodies is a quantity which can neither be increased nor diminished by any mutual action of such bodies, though it may be transformed into any one of the forms of which energy is susceptible.
Page 497 - As a unit of resistance, the international ohm, which is based upon the ohm equal to 10" units of resistance of the CGS system of electromagnetic units, and is represented by the resistance offered to an unvarying electric current by a column of mercury at the temperature of melting ice, 14.4521 grams in mass, of a constant cross-sectional area and of the length of 106.3 centimetres.
Page 262 - The vast influence which the ocean must exert, as a moderator of climate, here suggests itself. The heat of summer is stored up in the ocean, and slowly given out during the winter. This is one cause of the absence of extremes in an island climate.
Page 304 - When equal quantities of mechanical effect are produced by any means whatever from purely thermal sources, or lost in purely thermal effects, equal quantities of heat are put out of existence or are generated.
Page 600 - We want a small range of rapid vibrations, and we know no better than to make the whole series leading up to them. It is as though, in order to sound some little shrill octave of pipes in an organ, we were obliged to depress every key and every pedal, and to blow a young hurricane.
Page 292 - Heat gradually travels from the end in the flame toward the hand. Apply your fingers successively at different points nearer and nearer the flame ; you find that the nearer you approach the flame the hotter the wire is. The flow of heat through an unequally heated body, from places of higher to places of lower temperature, is called conduction; the body through which it travels is called the conductor.
Page 123 - Newton generalized the law of attraction into a statement that every particle of matter in the universe attracts every other particle with a force which varies directly as the product of their masses and inversely as the square of the distance between them; and he thence deduced the law of attraction for spherical shells of constant density.