MEEN 315 504 PRINCIPLES OF THERMODYNAMICS SPRING 2017 Homework Cover page Student Last Name Student First Name UIN HW Date Submitted 1 Grading Completion All problems attempted Quality Neatness clarity legible Accuracy Accuracy of selected problem s Cover page this page attached on the top and all pages stapled together Total 10 points Max Score 4 1 4 1 Your Score 10 This cover page should be completed and stapled to the top of your homework solution MEEN 315 504 PRINCIPLES OF THERMODYNAMICS SPRING 2017 Homework Assignment 1 Due Jan 24 2017 at the beginning of the class Problem 1 A swimming pool when filled to the top can hold 42 500 gallons of water It currently has 10 000 gallons of water in it How long will it take to fill the pool if three water hoses having flow rates of 10 gallons min 100 l hr and 200 cm3 s are to be used simultaneously to fill the pool Problem 2 A mid size family car has a mass of 3000 lbm With a full tank of gasoline it contains 106 BTU of chemical energy It is estimated that only 30 of the chemical energy of fuel is converted to the kinetic energy of the car Assuming an ideal case of no friction or drag calculate the maximum speed in miles per hour 1 mile 5 280 ft the car could obtain from accelerating from rest In reality explain the reasons why the car cannot attain this speed Problem 3 Give examples for three 03 closed systems and 03 open systems we encounter in everyday life Draw schematic of each system indicating the system boundary and any mass energy flow through the boundary In each system list at least two properties which you think important to describe that system Indicate whether each property is intensive I or extensive E Problem 4 In a particular day in the Spring outside air temperature rises from a morning low of 42 F to an afternoon high of 70 F a Express these temperatures in R K and C b Determine the temperature change in F R K and C from morning low to afternoon high c What conclusion do you draw about temperature change for F and R scales d What conclusion do you draw about temperature change for C and K scales Problem 5 A rigid gas tank has a total volume of 12 m3 It is partitioned into two chambers using a thin metal plate a membrane Each chamber contains nitrogen gas The nitrogen gas in section A has initial density of 1 6 kg m3 and the nitrogen gas in section B has a mass of 6 kg At a certain time the membrane is punctured internally When the gas inside the tank reaches equilibrium the final density of the nitrogen gas in the tank is found to be 1 8 kg m3 Determine the initial density kg m3 of nitrogen gas that existed in section B MEEN 315 504 PRINCIPLES OF THERMODYNAMICS SPRING 2017 When solving problems it is recommended to follow the systematic problem solving procedure as outlined in the below example Example Problem Solution Problem Statement The density of air inside a room is 1 16 kg m3 The length depth and height of the room are 10 m 8 m and 3 m respectively What is the mass of the air inside the room If acceleration due to gravity is 9 81 ms 2 what is the weight of the air Problem Solution Given Density of air 1 16 mkg3 Dimensions of the room 10 m X 8 m X 3 m Find Mass of the air Weight of the air System Assumptions No air is leaking from the room Uniform air density Basic Equation s mass density volume m v weight mass acceleration due to gravity w m g MEEN 315 504 PRINCIPLES OF THERMODYNAMICS Solution Calculate the mass m v kg m 1 16 3 10 8 3m3 m m 278 4 kg Now calculate the weight w m g m 1N w 278 4kg 9 81 2 m s 1kg 2 s w 2 731N SPRING 2017
View Full Document
Unlocking...