<text><span class="style10">hermodynamics (1 of 6)</span><span class="style7">Thermodynamics is the study of heat and temperature. Heat is a form of energy, and the temperature of a substance is a measure of its internal energy. One fundamental principle in the study of thermodynamics is the conservation of energy. This theory was developed in the late 19th century by about a dozen scientists, including James Joule (1818-89), a brewery-owner from the north of England, and Baron Herman von Helmholtz (1821-94), a German physiologist. Although there seemed to be plenty of evidence in the world that energy was not conserved, this important principle was eventually established.Much of the energy that seems to be lost in typical interactions - such as a box sliding across a floor - is converted into internal energy; in the case of the sliding box, this is the kinetic energy gained by the atoms and molecules within the box and the floor as they interact and are pulled from their equilibrium positions. The name given to the energy in the form of hidden motion of atoms and molecules is </span><span class="style26">thermal energy</span><span class="style7">. Strictly speaking, heat is transferred between two bodies as a result of a change in temperature, although the term `heat' is commonly used for the thermal energy as well. Processes that turn kinetic energy, which is the organized energy of a moving body, into thermal energy, which is the disorganized energy due to the motion of atoms, include friction and viscosity. In a steam engine, heat is turned into work.</span></text>
</content>
<content>
<layer>background</layer>
<id>26</id>
<text><span class="style10">. Work.</span><span class="style7"> Work done on a body by a constant force is the product of the magnitude of the force and the displacement of the body as a result of the action of the force: </span><span class="style26">W=Fd</span><span class="style7">.</span></text>
</content>
<content>
<layer>background</layer>
<id>23</id>
<text>ΓÇó MOTION AND FORCEΓÇó FORCES AFFECTING SOLIDS AND FLUIDSΓÇó THE HISTORY OF SCIENCEΓÇó ENERGYΓÇó ENGINES</text>
