When heating water for cooking food, it is common to use an electric or natural-gas cooktop. A metal pot with radius r=0.11m is filled with water to a depth of h=0.16m and heated on such a cooktop. The water is initially at a temperature of T0=25∘C. a. Enter an expression for the amount of heat required to raise the temperature of the water to its boiling point of Tv=100∘C in terms of r, h, T0, Tv, ρ and c. b. Calculate the amount of heat, in joules, required to raise the temperature of the water to its boiling point. Water has a density of ρ=1.000×103kg/m3 and a specific heat of c=4.186×103J/(kg⋅∘C) c. According to the U.S. Energy Information Administration, the average cost of electricity in the U.S. is about $0.10 per kilowatt-hour, or $0.028 per megajoule of electrical energy. Assuming all the electrical energy goes into heating the water on the cooktop, how much does it cost, in dollars, to heat the pot of water with electricity? Ignore the heat required to raise the temperature of the pot. d. According to the U.S. Energy Information Administration, the average cost of natural gas in the U.S. is about $10.00 per thousand cubic feet, which amounts to $0.010 per megajoule of released energy when the gas is burned. Assuming all the energy released in combustion goes into heating the water on the cooktop, how much does it cost, in dollars, to heat the pot of water with natural gas? Ignore the heat required to raise the temperature of the pot.
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.
When heating water for cooking food, it is common to use an electric or natural-gas cooktop. A metal pot with radius r=0.11m is filled with water to a depth of h=0.16m and heated on such a cooktop. The water is initially at a temperature of T0=25∘C.
a. Enter an expression for the amount of heat required to raise the temperature of the water to its boiling point of Tv=100∘C in terms of r, h, T0, Tv, ρ and c.
b. Calculate the amount of heat, in joules, required to raise the temperature of the water to its boiling point. Water has a density of ρ=1.000×103kg/m3 and a specific heat of c=4.186×103J/(kg⋅∘C)
c. According to the U.S. Energy Information Administration, the average cost of electricity in the U.S. is about $0.10 per kilowatt-hour, or $0.028 per megajoule of electrical energy. Assuming all the electrical energy goes into heating the water on the cooktop, how much does it cost, in dollars, to heat the pot of water with electricity? Ignore the heat required to raise the temperature of the pot.
d. According to the U.S. Energy Information Administration, the average cost of natural gas in the U.S. is about $10.00 per thousand cubic feet, which amounts to $0.010 per megajoule of released energy when the gas is burned. Assuming all the energy released in combustion goes into heating the water on the cooktop, how much does it cost, in dollars, to heat the pot of water with natural gas? Ignore the heat required to raise the temperature of the pot.
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