Heat and Temperature Flashcards
Temperature
Measurement of the Average Kinetic energy of the substance being measured
Heat
Quantity that causes an increase in the temperature of a body when it is added to the body and a decrease in temperature when it is removed from a body provided the body does not undergo a change of state during the process.
Heat Energy Movement
Always transferred from an area of higher temperature to an area of lower temperature regardless of the total energy in either area.
Specific Heat
Defined as the amount of energy in calories required to raise the temperature of 1 gram of the substance by 1 degree Celcius. Water is used as the standard and its specific heat is 1cal/(gm x C)
Heat energy Equation
Q=MCdeltaT Q=energy in calories M=Mass C=specific heat in calories/(gmxC) T= temperature change
Specific Heat of Ice
0.5 cal/(gmxC)
Heat of fusion of Ice at 0C
80cal/gm
Heat of vaporization of water at 100C
540cal/gm
Specific heat of steam
0.5 cal/(gmxC)
Conduction
The principal mode of heat transfer in solids
Convection
30%
The principle method of heat transfer in liquids and gases
Radiation
40%
Means by which thermal energy is transferred by electromagnetic waves.
The rate at which an object radiates energy is a function of the absolute temperature of the object.
Forced Convection
A pump circulates fluid from the bottom of the radiator to the water jacket of the engine. This brings the cool water to the warm surface of the engine, helping speed the convection current.
Stefan-Boltzmann Law
E=eo(T1^4-T2^4)
o is Stefan’s constant
o=4.8 x 10^-8 kcal/(m^2 x hr x K^4)
e=emissivity
Heat of Vaporization (evaporation)
20%
Heat of vaporization is about 580 cal/gm at normal body temperatures.
