A large cylindrical coffee pot in a coffee shop filled with 10.0 kg of hot coffee at temperature T = 95.0 ° C rests on a wooden table. The steel pot has radius r = 8.00 cm and height h = 50.0 cm and an emissivity e = 0.600. See figure. Assume that all heat loss is radiative through the side and top of the pot, given that wood is a relatively poor thermal conductor. The coffee shop ambient temperature T = 20.0 ° C. a) Find the rate at which the coffee losses heat. b) Assuming constant heat loss rate, what is the coffee temperature after 10.0 minutes have elapsed? Cw = 4.19 x 103 J/kg °C, ρw = 1.00 x 103 kg/m3, σ = 5.67 x 10 -8 W/m2 K4
Energy transfer
The flow of energy from one region to another region is referred to as energy transfer. Since energy is quantitative; it must be transferred to a body or a material to work or to heat the system.
Molar Specific Heat
Heat capacity is the amount of heat energy absorbed or released by a chemical substance per the change in temperature of that substance. The change in heat is also called enthalpy. The SI unit of heat capacity is Joules per Kelvin, which is (J K-1)
Thermal Properties of Matter
Thermal energy is described as one of the form of heat energy which flows from one body of higher temperature to the other with the lower temperature when these two bodies are placed in contact to each other. Heat is described as the form of energy which is transferred between the two systems or in between the systems and their surrounding by the virtue of difference in temperature. Calorimetry is that branch of science which helps in measuring the changes which are taking place in the heat energy of a given body.
A large cylindrical coffee pot in a coffee shop filled with 10.0 kg of hot coffee at temperature T = 95.0 ° C rests on a wooden table. The steel pot has radius r = 8.00 cm and height h = 50.0 cm and an emissivity e = 0.600. See figure. Assume that all heat loss is radiative through the side and top of the pot, given that wood is a relatively poor thermal conductor. The coffee shop ambient temperature T = 20.0 ° C. a) Find the rate at which the coffee losses heat. b) Assuming constant heat loss rate, what is the coffee temperature after 10.0 minutes have elapsed? Cw = 4.19 x 103 J/kg °C, ρw = 1.00 x 103 kg/m3, σ = 5.67 x 10 -8 W/m2 K4
Given information:
Mass of coffee (m) = 10.0 kg
Initial temperature of the coffee (Tc) = 95 0C = 368 0K
The ambient atmospheric temperature (Ta) = 293 0K
The radius of the pot (r) = 8 cm = 0.08 m
The height of the pot (h) = 50 cm = 0.5 m
The emissivity of the steel surface (e) = 0.600
The Stephen-Boltzmann constant (σ) = 5.67 x 10 -8 W/m2
The rate of heat loss of the coffee is given as:
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