Coefficient of Thermal Expansion
Introduction The main theory of the experiment is that an object needs an amount of heat for it to change a unit mass by 1 degree in temperature. The objectives of the experiment are to determine the specific heat of metal specimens using the method of mixture, to measure the equipment properly, to carefully measure the temperature of the equipment, to be patient while waiting for the output of the experiment and to be precise in computing for the specific heat of the specimen.
Theory
Blanza, J., Guevara, C., Morsiquillo, A., Nacu, G. (2012) noted that the transfer of energy is made by temperature difference between the object and its surroundings. The common units for heat are calorie and BTU (British Thermal Unit). A calorie is the amount of heat needed to raise the temperature of one gram of water by 1°C while BTU is the amount of heat needed to raise the temperature of one pound of water by 1°F. The factors that affect the transfer of heat energy are substance’s mass, change in temperature and the specific heat capacity of the substance being heated. Under normal conditions, the temperature change (∆T¬) is approximately proportional to the heat (Q). The constant proportionality is called the heat capacity. Given by the equation: Heat capacity = Q / ∆T While specific heat capacity (c) is the heat capacity per unit mass. Given by the equation: c = Q/m∆T where: c - specific heat capacity
Q – heat m - mass ∆T – change in temperature
And derived from that equation we could get heat: Q = mc∆T
The measurement of heat is often made by applying the law of conservation of energy. Calorimetry is the application of this law. Qlost=Qgained For an instance a metal specimen is heated and then placed in cold water in a calorimeter up. The meal specimen will lose heat while the cold water, the calorimeter cup, and stirrer will gain heat. Given by the equation: mxcx(Te-Tx) = (mwcw+mccc+mscs)(Te-Ti) where: mx,mw,mc,ms – the mass of specimen,
Theory
Blanza, J., Guevara, C., Morsiquillo, A., Nacu, G. (2012) noted that the transfer of energy is made by temperature difference between the object and its surroundings. The common units for heat are calorie and BTU (British Thermal Unit). A calorie is the amount of heat needed to raise the temperature of one gram of water by 1°C while BTU is the amount of heat needed to raise the temperature of one pound of water by 1°F. The factors that affect the transfer of heat energy are substance’s mass, change in temperature and the specific heat capacity of the substance being heated. Under normal conditions, the temperature change (∆T¬) is approximately proportional to the heat (Q). The constant proportionality is called the heat capacity. Given by the equation: Heat capacity = Q / ∆T While specific heat capacity (c) is the heat capacity per unit mass. Given by the equation: c = Q/m∆T where: c - specific heat capacity
Q – heat m - mass ∆T – change in temperature
And derived from that equation we could get heat: Q = mc∆T
The measurement of heat is often made by applying the law of conservation of energy. Calorimetry is the application of this law. Qlost=Qgained For an instance a metal specimen is heated and then placed in cold water in a calorimeter up. The meal specimen will lose heat while the cold water, the calorimeter cup, and stirrer will gain heat. Given by the equation: mxcx(Te-Tx) = (mwcw+mccc+mscs)(Te-Ti) where: mx,mw,mc,ms – the mass of specimen,
References: Blanza, J., Guevara, C., Morsiquillo, A., Nacu, G.(2012) Physics 104 Laboratory Manual College Physics I http://scienceworld.wolfram.com/physics/SpecificHeat.html http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/spht.html