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A 22 g block of ice is cooled to −68◦C. It is added to 521g of water in an 67g copper calorimeter at a temperature of 21◦C.
Find the final temperature. The specific heat of copper is 387 J/kg ·◦C and of ice is 2090 J/kg ·◦C . The latent heat of fusion of water is 3.33 × 105 J/kg and its specific heat is4186J/kg·◦C.
Answer in units of ◦C.
The brick wall (of thermal conductivity 0.86 W/m ·◦ C) of a building has dimensions of 3.7m by 16m and is13cm thick.
How much heat flows through the wall in a 17.4 h period when the average inside and outside temperatures are, respectively, 9 ◦C and 8◦C?
Answer in units of MJ.
Three liquids are at temperatures of 13◦C, 19◦C, and 31◦C, respectively. Equal masses of the first two liquids are mixed, and the equi- librium temperature is 16◦C. Equal masses of the second and third are then mixed, and the equilibrium temperature is 24.3◦C.
Find the equilibrium temperature when equal masses of the first and third are mixed.
Answer in units of ◦C.
Determine the specific volume of wet steam at 68 bar.
Determine the specific internal energy, specific enthalpy and specific volume of steam at a pressure of 3 bar (300 kN m-2) when it is .82 dry. What is the saturate temperature?
Determine the specific internal energy in wet steam at a pressure of 4 bar when it has a dryness fraction of 0.87.
Determine the specific enthalpy of wet steam at a pressure of 70 kN m-2 and having a dryness fraction of 0.85.
Nitrogen gas having a mass of 0.8 kg at 110 kPa and 50℃ is contained in a cylinder. The piston is moved compressing nitrogen until the pressure becomes 1.1 MPa and temperature becomes 200℃. The work done during the process is 50 kJ. Find the heat transferred from the nitrogen to the surroundings. Use 𝑐𝑣 for nitrogen = 0.75 kJ/kg-K.
A system has N distinguishable particles. Each particle has two non-degenerate states
with level separation of 0.15 eV. Calculate the average number of the particles in each
state when the system is in thermal equilibrium with the bath temperature of 300 K.
(3)
Explain entropy
