a42 - either a change in temperature or a change in...

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Transfer of Thermal Energy A common unit of energy is the calorie . A calorie is defined as the amount of heat that is needed to raise the temperature of one gram of water one degree centigrade. Modern convention uses a unit of energy called a joule. A calorie is equal to 4.184 joules. A joule is approximately the energy needed to lift 2000 grams a distance of 10 centimeters. Heat is transferred by either direct transfer from one object touching another or by the emission of radiation in the form of infrared radiation. Two results can occur as a result of this transfer of thermal energy. A substance can undergo
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Unformatted text preview: either a change in temperature or a change in physical state. When a substance exchanges heat with its surroundings without changing its physical state, the substance will undergo a change in temperature. This change in temperature depends on a property called specific heat capacity. Specific heat capacity is the "heat needed to produce a given temperature change (in Celsius or Kelvin) per gram of substance" and is expressed in the units J/gK. Specific heat capacity depends on both the type of substance and the mass of the substance. The " " means "change in" and "q" represents the quantity of heat....
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This note was uploaded on 04/28/2010 for the course ENGN 45 taught by Professor Wendy during the Fall '09 term at City College of San Francisco.

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