Lessons in elementary physics / by Balfour Stewart.

  • Stewart, Balfour, 1828-1887.
Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: Lessons in elementary physics / by Balfour Stewart. Source: Wellcome Collection.

    487/502 (page 467)
    Recapitulation.— It may bo de.sirable, before concluclin.ar, to recapitulate the various transmutations of energy. 4-55. Visible Energy. Visible Energy of Motion is transmuted into visible potential energy when a stone is pro- jected upwards and lodged on the top of a house (xVrt. iii), and it is transmuted into heat when friction or percussion stops a body in motion (.Vr(. 113). It is transmuted into electrical sep.aration when we work the electric machine (Art. 351), and into electricity in motion when a revolving conductor is brought between the poles of a power- ful magnet (Art. 411). Visible Potential Energy is generally converted into visible energy of motion, and through it into the other forms of energy. 456. Heat.—This species of energy is converted into visible motion in the heat engine (Art. 245). It is converted into radiant energy when a hot body radiates (Art. 334). It is converted into electrical separation when tourmalines ami other gems are heated (Art. 339). It is converted into electri- city in motion in the thermo-electric pile (Art. 393). Finallv, it is converted into chemical separation when a body is decomposed by heat (Art. 215). 457. Radiant Energy.—This species of energy is con- verted into heat when radiant light or heat is absorbed by a body (Art. 344), and it is converted into chemical separation when a ray of sunlight decomposes chloride of silver in photography, or carbonic acid in the leaves of plants (.\rt. 453)- 458. Electrical Separation.—The energy of electrical separation is transformed into visible motion when two oppositely electrified bodies approach e.ach other (.-Vrt. 339), and it is transformed into the energy of electricity in motion when two such bodies arc connected together by means of a wire (Art. 359). 459. Electricity in Motion. -This form of energy is con- verted into visible motion when currents act on one another, as in Art. 408 ; it is converted into absorbed heat when ;i current meets with resistance (Art. 430) ; ami into chemical separation when a current decompo.ses a compouml bodv (.Art. 436). 460. Chemical Separation.—This form of energy is Ir.ins-