<text><span class="style10">hermodynamics (2 of 6)Work and energy</span><span class="style7">When a force acts on a body, causing acceleration in the direction of the force, </span><span class="style26">work</span><span class="style7"> is done. The work done on a body by a constant force is defined as the product of the magnitude of the force and the consequent displacement of the body in the direction of the forceThe unit of work is the </span><span class="style26">joule</span><span class="style7"> (sometimes referred to as the </span><span class="style26">newton meter</span><span class="style7">). A joule (J) is defined as the work done on a body when it is displaced 1 meter as the result of the action of a force of 1 newton acting in the direction of motion: 1 J = 1 N m The result may be expressed more generally.</span><span class="style26">Energy</span><span class="style7"> is the capacity of a body to do work. The total energy stored in a </span><span class="style26">closed system</span><span class="style7"> - one in which no external forces are experienced - remains constant, however it may be transformed. This is the principle of </span><span class="style26">conservation of energy</span><span class="style7">. It may take the form of mechanical energy (kinetic or potential; see below), electrical energy, chemical energy, or heat energy. There are also other forms of energy, including gravitational, magnetic, the energy of electromagnetic radiation, and the energy of matter.</span></text>
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<text><span class="style10">. Work done.</span><span class="style7"> A exerts a force </span><span class="style26">F</span><span class="style7"> on B and as a result B moves to position B with displacement </span><span class="style26">d</span><span class="style7"> at angle q to the line of </span><span class="style26">F</span><span class="style7">. Work </span><span class="style26">W = Fd cos</span><span class="style7"> q. </span></text>
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<text>ΓÇó MOTION AND FORCEΓÇó FORCES AFFECTING SOLIDS AND FLUIDSΓÇó THE HISTORY OF SCIENCEΓÇó ENERGYΓÇó ENGINES</text>