Homework+assignment+3

# Homework+assignment+3 - period of time the temperature and...

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Homework 3 (due 2/7/2012) 1. Please describe the application conditions for following energy balance equations: a. PdV Q dU - = b. PdV Q dM H dU - + = c. W Q U U M + = - 1 2 d. s W Q H H M + = - 1 2 2. Please write down the energy balance equation under following conditions: a. 1 kg of steam contained in a horizontal frictionless piston and cylinder is heated at a constant pressure of 1.013 bar from 125 to such a temperature that its volume doubles. b. 1 kg of steam contained in a horizontal frictionless piston and cylinder is heated at a constant volume to a pressure that is twice the initial pressure. 3. An isolated chamber with rigid walls is divided into two equal compartments, one containing ideal gas at 1 MPa and 500 K and the other evacuated. The partition between the compartments ruptures. After the passage of a sufficiently long
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Unformatted text preview: period of time, the temperature and pressure are found to be uniform throughout the chamber. Find out the final temperature and pressure in the chamber. 4. The voltage drop across an electrical resistor is 10 Volts and the current through it is 1 Ampere. The total heat capacity of the resistor is 20 J/K, and heat is dissipated from the resistor to the surrounding air according to the relation: ( 29 a T T h Q--= • Where T a is the ambient air temperature, 25 . T is the temperature of the ℃ resistor, and h is the heat transfer coefficient which is equal to 0.2 J/Ks. Compute the steady state temperature of the resistor, that is, the temperature of the resistor when the energy loss from the resistor is equal to the electrical energy input....
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## This note was uploaded on 02/20/2012 for the course CBEMS 45B taught by Professor Shi during the Spring '12 term at UC Irvine.

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