A certain pond absorbs I = 980 W/m2 for a time period of an hour from the sun. Assume that all of this energy is used to raise the temperature of the pond. The pond water fills a hemisphere of radius r = 2.27 m and has a density ρ = 1000 kg/m3. The specific heat of the pond water is c = 4186 J/(kg⋅K). a)What is the change in temperature ΔT in kelvins of the pond due to this energy transfer? b)What is the change in the internal energy of the pond ΔU in joules, assuming that it does no work and loses no energy as heat? c)If the initial temperature of the pond was T = 20.0°C, what would be the change in the entropy ΔS of the pond, in joules per kelvin?
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 certain pond absorbs I = 980 W/m2 for a time period of an hour from the sun. Assume that all of this energy is used to raise the temperature of the pond. The pond water fills a hemisphere of radius r = 2.27 m and has a density ρ = 1000 kg/m3. The specific heat of the pond water is c = 4186 J/(kg⋅K).
a)What is the change in temperature ΔT in kelvins of the pond due to this energy transfer?
b)What is the change in the internal energy of the pond ΔU in joules, assuming that it does no work and loses no energy as heat?
c)If the initial temperature of the pond was T = 20.0°C, what would be the change in the entropy ΔS of the pond, in joules per kelvin?
d)If the pond were at a temperature of T = 0.0°C and covered by a d = 0.10 m thick layer of ice at this same temperature, how long Δt in hours would it take to melt the ice? The latent heat of fusion for ice is Lf = 334 kJ/kg and its density is ρice = 917 kg/m3. Assume that the layer of ice has the form of a cylinder of thickness d and cross-sectional radius r.
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d)If the pond were at a temperature of T = 0.0°C and covered by a d = 0.10 m thick layer of ice at this same temperature, how long Δt in hours would it take to melt the ice? The latent heat of fusion for ice is Lf = 334 kJ/kg and its density